Controllers for optically-switchable devices

ABSTRACT

This disclosure relates generally to optically-switchable devices, and more particularly, to systems, apparatus, and methods for controlling optically-switchable devices. In some implementations, the apparatus includes an interface for communicating with window controllers, and the apparatus includes one or more processors. A processor can be configured to cause status information received from a window controller to be processed. The status information can indicate at least a tint status of one or more optically-switchable devices controlled by the window controller. In response to receiving the status information, one or more tint commands can be sent via the interface to the window controller.

PRIORITY DATA

This patent document is a continuation of and claims priority toco-pending and commonly-assigned U.S. patent application Ser. No.16/948,340, titled CONTROLLERS FOR OPTICALLY-SWITCHABLE DEVICES, byBrown et al., filed Sep. 14, 2020 (Attorney Docket No. VIEWP084C1),which is a continuation of and claims priority to commonly-assigned U.S.patent application Ser. No. 15/334,832, titled CONTROLLERS FOROPTICALLY-SWITCHABLE DEVICES, by Brown et al., filed Oct. 26, 2016(Attorney Docket No. VIEWP084), which (i) is a continuation-in-part ofand claims priority to commonly-assigned U.S. patent application Ser.No. 14/998,019, titled MULTI-SENSOR HAVING A RING OF PHOTOSENSORS, byBrown et al., filed Oct. 6, 2015 (Attorney Docket No. VIEWP081) andwhich (ii) also claims priority to commonly-assigned U.S. ProvisionalPatent Application No. 62/248,181, titled CONTROLLERS FOROPTICALLY-SWITCHABLE DEVICES, by Brown et al., filed Oct. 29, 2015(Attorney Docket No. VIEWP083P), each of which is incorporated byreference in their entireties and for all purposes.

TECHNICAL FIELD

This disclosure relates generally to optically-switchable devices, andmore particularly, to controllers for optically-switchable devices.

BACKGROUND

The development and deployment of optically-switchable windows haveincreased as considerations of energy efficiency and system integrationgain momentum. Electrochromic windows are a promising class ofoptically-switchable windows. Electrochromism is a phenomenon in which amaterial exhibits a reversible electrochemically-mediated change in oneor more optical properties when stimulated to a different electronicstate. Electrochromic materials and the devices made from them may beincorporated into, for example, windows for home, commercial, or otheruse. The color, tint, transmittance, absorbance, or reflectance ofelectrochromic windows can be changed by inducing a change in theelectrochromic material, for example, by applying a voltage across theelectrochromic material. Such capabilities can allow for control overthe intensities of various wavelengths of light that may pass throughthe window. One area of relatively recent interest is in intelligentcontrol systems and algorithms for driving optical transitions inoptically-switchable windows to provide desirable lighting conditionswhile reducing the power consumption of such devices and improving theefficiency of systems with which they are integrated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional side view of an example electrochromicwindow 100 in accordance with some implementations.

FIG. 2 illustrates an example control profile in accordance with someimplementations.

FIG. 3 shows a block diagram of an example network system operable tocontrol a plurality of IGUs in accordance with some implementations.

FIG. 4 shows a block diagram of an example master controller (MC) inaccordance with some implementations.

FIG. 5 shows a block diagram of an example network controller (NC) inaccordance with some implementations.

FIG. 6 shows a circuit schematic diagram of an example window controller(WC) in accordance with some implementations.

FIG. 7 shows a diagram of an example connection architecture forcoupling a window controller to an IGU in accordance with someimplementations.

FIG. 8 shows a block diagram of example modules of a network controllerin accordance with some implementations.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

The following detailed description is directed to specific exampleimplementations for purposes of disclosing the subject matter. Althoughthe disclosed implementations are described in sufficient detail toenable those of ordinary skill in the art to practice the disclosedsubject matter, this disclosure is not limited to particular features ofthe specific example implementations described herein. On the contrary,the concepts and teachings disclosed herein can be implemented andapplied in a multitude of different forms and ways without departingfrom their spirit and scope. For example, while the disclosedimplementations focus on electrochromic windows (also referred to assmart windows), some of the systems, devices and methods disclosedherein can be made, applied or used without undue experimentation toincorporate, or while incorporating, other types of optically-switchabledevices. Some other types of optically-switchable devices include liquidcrystal devices, suspended particle devices, and even micro-blinds,among others. For example, some or all of such otheroptically-switchable devices can be powered, driven or otherwisecontrolled or integrated with one or more of the disclosedimplementations of controllers described herein. Additionally, in thefollowing description, the phrases “operable to,” “adapted to,”“configured to,” “designed to,” “programmed to,” or “capable of” may beused interchangeably where appropriate.

Example Electrochromic Window Architecture

FIG. 1 shows a cross-sectional side view of an example electrochromicwindow 100 in accordance with some implementations. An electrochromicwindow is one type of optically-switchable window that includes anelectrochromic device (ECD) used to provide tinting or coloring. Theexample electrochromic window 100 can be manufactured, configured orotherwise provided as an insulated glass unit (IGU) and will hereinafteralso be referred to as IGU 100. This convention is generally used, forexample, because it is common and because it can be desirable to haveIGUs serve as the fundamental constructs for holding electrochromicpanes (also referred to as “lites”) when provided for installation in abuilding. An IGU lite or pane may be a single substrate or amulti-substrate construct, such as a laminate of two substrates. IGUs,especially those having double- or triple-pane configurations, canprovide a number of advantages over single pane configurations; forexample, multi-pane configurations can provide enhanced thermalinsulation, noise insulation, environmental protection and/or durabilitywhen compared with single-pane configurations. A multi-paneconfiguration also can provide increased protection for an ECD, forexample, because the electrochromic films, as well as associated layersand conductive interconnects, can be formed on an interior surface ofthe multi-pane IGU and be protected by an inert gas fill in the interiorvolume, 108, of the IGU.

FIG. 1 more particularly shows an example implementation of an IGU 100that includes a first pane 104 having a first surface S1 and a secondsurface S2. In some implementations, the first surface S1 of the firstpane 104 faces an exterior environment, such as an outdoors or outsideenvironment. The IGU 100 also includes a second pane 106 having a firstsurface S3 and a second surface S4. In some implementations, the secondsurface S4 of the second pane 106 faces an interior environment, such asan inside environment of a home, building or vehicle, or a room orcompartment within a home, building or vehicle.

In some implementations, each of the first and the second panes 104 and106 are transparent or translucent—at least to light in the visiblespectrum. For example, each of the panes 104 and 106 can be formed of aglass material and especially an architectural glass or othershatter-resistant glass material such as, for example, a silicon oxide(SO_(x))-based glass material. As a more specific example, each of thefirst and the second panes 104 and 106 can be a soda-lime glasssubstrate or float glass substrate. Such glass substrates can becomposed of, for example, approximately 75% silica (SiO₂) as well asNa₂O, CaO, and several minor additives. However, each of the first andthe second panes 104 and 106 can be formed of any material havingsuitable optical, electrical, thermal, and mechanical properties. Forexample, other suitable substrates that can be used as one or both ofthe first and the second panes 104 and 106 can include other glassmaterials as well as plastic, semi-plastic and thermoplastic materials(for example, poly(methyl methacrylate), polystyrene, polycarbonate,allyl diglycol carbonate, SAN (styrene acrylonitrile copolymer),poly(4-methyl-1-pentene), polyester, polyamide), or mirror materials. Insome implementations, each of the first and the second panes 104 and 106can be strengthened, for example, by tempering, heating, or chemicallystrengthening.

Generally, each of the first and the second panes 104 and 106, as wellas the IGU 100 as a whole, is a rectangular solid. However, in someother implementations other shapes are possible and may be desired (forexample, circular, elliptical, triangular, curvilinear, convex orconcave shapes). In some specific implementations, a length “L” of eachof the first and the second panes 104 and 106 can be in the range ofapproximately 20 inches (in.) to approximately 10 feet (ft.), a width“W” of each of the first and the second panes 104 and 106 can be in therange of approximately 20 in. to approximately 10 ft., and a thickness“T” of each of the first and the second panes 104 and 106 can be in therange of approximately 0.3 millimeter (mm) to approximately 10 mm(although other lengths, widths or thicknesses, both smaller and larger,are possible and may be desirable based on the needs of a particularuser, manager, administrator, builder, architect or owner). In exampleswhere thickness T of substrate 104 is less than 3 mm, typically thesubstrate is laminated to an additional substrate which is thicker andthus protects the thin substrate 104. Additionally, while the IGU 100includes two panes (104 and 106), in some other implementations, an IGUcan include three or more panes. Furthermore, in some implementations,one or more of the panes can itself be a laminate structure of two,three, or more layers or sub-panes.

The first and second panes 104 and 106 are spaced apart from one anotherby a spacer 118, which is typically a frame structure, to form aninterior volume 108. In some implementations, the interior volume isfilled with Argon (Ar), although in some other implementations, theinterior volume 108 can be filled with another gas, such as anothernoble gas (for example, krypton (Kr) or xenon (Xn)), another (non-noble)gas, or a mixture of gases (for example, air). Filling the interiorvolume 108 with a gas such as Ar, Kr, or Xn can reduce conductive heattransfer through the IGU 100 because of the low thermal conductivity ofthese gases as well as improve acoustic insulation due to theirincreased atomic weights. In some other implementations, the interiorvolume 108 can be evacuated of air or other gas. Spacer 118 generallydetermines the height “C” of the interior volume 108; that is, thespacing between the first and the second panes 104 and 106. In FIG. 1,the thickness of the ECD, sealant 120/122 and bus bars 126/128 is not toscale; these components are generally very thin but are exaggerated herefor ease of illustration only. In some implementations, the spacing “C”between the first and the second panes 104 and 106 is in the range ofapproximately 6 mm to approximately 30 mm. The width “D” of spacer 118can be in the range of approximately 5 mm to approximately 15 mm(although other widths are possible and may be desirable).

Although not shown in the cross-sectional view, spacer 118 is generallya frame structure formed around all sides of the IGU 100 (for example,top, bottom, left and right sides of the IGU 100). For example, spacer118 can be formed of a foam or plastic material. However, in some otherimplementations, spacers can be formed of metal or other conductivematerial, for example, a metal tube or channel structure having at least3 sides, two sides for sealing to each of the substrates and one side tosupport and separate the lites and as a surface on which to apply asealant, 124. A first primary seal 120 adheres and hermetically sealsspacer 118 and the second surface S2 of the first pane 104. A secondprimary seal 122 adheres and hermetically seals spacer 118 and the firstsurface S3 of the second pane 106. In some implementations, each of theprimary seals 120 and 122 can be formed of an adhesive sealant such as,for example, polyisobutylene (PIB). In some implementations, IGU 100further includes secondary seal 124 that hermetically seals a borderaround the entire IGU 100 outside of spacer 118. To this end, spacer 118can be inset from the edges of the first and the second panes 104 and106 by a distance “E.” The distance “E” can be in the range ofapproximately 4 mm to approximately 8 mm (although other distances arepossible and may be desirable). In some implementations, secondary seal124 can be formed of an adhesive sealant such as, for example, apolymeric material that resists water and that adds structural supportto the assembly, such as silicone, polyurethane and similar structuralsealants that form a water tight seal.

In the particular configuration and form factor depicted in FIG. 1, theECD coating on surface S2 of substrate 104 extends about its entireperimeter to and under spacer 118. This configuration is functionallydesirable as it protects the edge of the ECD within the primary sealant120 and aesthetically desirable because within the inner perimeter ofspacer 118 there is a monolithic ECD without any bus bars or scribelines. Such configurations are described in more detail in U.S. Pat. No.8,164,818, issued Apr. 24, 2012 and titled ELECTROCHROMIC WINDOWFABRICATION METHODS (Attorney Docket No. VIEWP006), U.S. patentapplication Ser. No. 13/456,056 filed Apr. 25, 2012 and titledELECTROCHROMIC WINDOW FABRICATION METHODS (Attorney Docket No.VIEWP006X1), PCT Patent Application No. PCT/US2012/068817 filed Dec. 10,2012 and titled THIN-FILM DEVICES AND FABRICATION (Attorney Docket No.VIEWP036WO), U.S. patent application Ser. No. 14/362,863 filed Jun. 4,2014 and titled THIN-FILM DEVICES AND FABRICATION (Attorney Docket No.VIEWP036US), and PCT Patent Application No. PCT/US2014/073081, filedDec. 13, 2014 and titled THIN-FILM DEVICES AND FABRICATION (AttorneyDocket No. VIEWP036X1WO), all of which are hereby incorporated byreference in their entireties and for all purposes.

In the implementation shown in FIG. 1, an ECD 110 is formed on thesecond surface S2 of the first pane 104. In some other implementations,ECD 110 can be formed on another suitable surface, for example, thefirst surface S1 of the first pane 104, the first surface S3 of thesecond pane 106 or the second surface S4 of the second pane 106. The ECD110 includes an electrochromic (“EC”) stack 112, which itself mayinclude one or more layers. For example, the EC stack 112 can include anelectrochromic layer, an ion-conducting layer, and a counter electrodelayer. In some implementations, the electrochromic layer is formed ofone or more inorganic solid materials. The electrochromic layer caninclude or be formed of one or more of a number of electrochromicmaterials, including electrochemically-cathodic orelectrochemically-anodic materials. For example, metal oxides suitablefor use as the electrochromic layer can include tungsten oxide (WO₃) anddoped formulations thereof. In some implementations, the electrochromiclayer can have a thickness in the range of approximately 0.05 μm toapproximately 1 μm.

In some implementations, the counter electrode layer is formed of aninorganic solid material. The counter electrode layer can generallyinclude one or more of a number of materials or material layers that canserve as a reservoir of ions when the EC device 110 is in, for example,the transparent state. In certain implementations, the counter electrodenot only serves as an ion storage layer but also colors anodically. Forexample, suitable materials for the counter electrode layer includenickel oxide (NiO) and nickel tungsten oxide (NiWO), as well as dopedforms thereof, such as nickel tungsten tantalum oxide, nickel tungstentin oxide, nickel vanadium oxide, nickel chromium oxide, nickel aluminumoxide, nickel manganese oxide, nickel magnesium oxide, nickel tantalumoxide, nickel tin oxide as non-limiting examples. In someimplementations, the counter electrode layer can have a thickness in therange of approximately 0.05 μm to approximately 1 μm.

The ion-conducting layer serves as a medium through which ions aretransported (for example, in the manner of an electrolyte) when the ECstack 112 transitions between optical states. In some implementations,the ion-conducting layer is highly conductive to the relevant ions forthe electrochromic and the counter electrode layers, but also hassufficiently low electron conductivity such that negligible electrontransfer (electrical shorting) occurs during normal operation. A thinion-conducting layer with high ionic conductivity enables fast ionconduction and consequently fast switching for high performance ECdevices 110. In some implementations, the ion-conducting layer can havea thickness in the range of approximately 1 nm to approximately 500 nm,more generally in the range of about 5 nm to about 100 nm thick. In someimplementations, the ion-conducting layer also is an inorganic solid.For example, the ion-conducting layer can be formed from one or moresilicates, silicon oxides (including silicon-aluminum-oxide), tungstenoxides (including lithium tungstate), tantalum oxides, niobium oxides,lithium oxide and borates. These materials also can be doped withdifferent dopants, including lithium; for example, lithium-doped siliconoxides include lithium silicon-aluminum-oxide, lithium phosphorousoxynitride (LiPON) and the like.

In some other implementations, the electrochromic layer and the counterelectrode layer are formed immediately adjacent one another, sometimesin direct contact, without an ion-conducting layer in between and thenan ion conductor material formed in situ between the electrochromic andcounter electrode layers. A further description of suitable devices isfound in U.S. Pat. No. 8,764,950, titled ELECTROCHROMIC DEVICES, by Wanget al., issued Jul. 1, 2014 and U.S. Pat. No. 9,261,751, titledELECTROCHROMIC DEVICES, by Pradhan et al., issued Feb. 16, 2016, each ofwhich is hereby incorporated by reference in its entirety and for allpurposes. In some implementations, the EC stack 112 also can include oneor more additional layers such as one or more passive layers. Forexample, passive layers can be used to improve certain opticalproperties, to provide moisture or to provide scratch resistance. Theseor other passive layers also can serve to hermetically seal the EC stack112. Additionally, various layers, including conducting layers (such asthe first and the second TCO layers 114 and 116 described below), can betreated with anti-reflective or protective oxide or nitride layers.

The selection or design of the electrochromic and counter electrodematerials generally governs the possible optical transitions. Duringoperation, in response to a voltage generated across the thickness ofthe EC stack 112 (for example, between the first and the second TCOlayers 114 and 116), the electrochromic layer transfers or exchangesions to or from the counter electrode layer to drive the electrochromiclayer to the desired optical state. In some implementations, to causethe EC stack 112 to transition to a transparent state, a positivevoltage is applied across the EC stack 112 (for example, such that theelectrochromic layer is more positive than the counter electrode layer).In some such implementations, in response to the application of thepositive voltage, the available ions in the stack reside primarily inthe counter electrode layer. When the magnitude of the potential acrossthe EC stack 112 is reduced or when the polarity of the potential isreversed, ions are transported back across the ion conducting layer tothe electrochromic layer causing the electrochromic material totransition to an opaque state (or to a “more tinted,” “darker” or “lesstransparent” state). Conversely, in some other implementations usingelectrochromic layers having different properties, to cause the EC stack112 to transition to an opaque state, a negative voltage can be appliedto the electrochromic layer relative to the counter electrode layer. Insuch implementations, when the magnitude of the potential across the ECstack 112 is reduced or its polarity reversed, the ions are transportedback across the ion conducting layer to the electrochromic layer causingthe electrochromic material to transition to a clear or “bleached” state(or to a “less tinted”, “lighter” or “more transparent” state).

In some implementations, the transfer or exchange of ions to or from thecounter electrode layer also results in an optical transition in thecounter electrode layer. For example, in some implementations theelectrochromic and counter electrode layers are complementary coloringlayers. More specifically, in some such implementations, when or afterions are transferred into the counter electrode layer, the counterelectrode layer becomes more transparent, and similarly, when or afterthe ions are transferred out of the electrochromic layer, theelectrochromic layer becomes more transparent. Conversely, when thepolarity is switched, or the potential is reduced, and the ions aretransferred from the counter electrode layer into the electrochromiclayer, both the counter electrode layer and the electrochromic layerbecome less transparent.

In one more specific example, responsive to the application of anappropriate electric potential across a thickness of EC stack 112, thecounter electrode layer transfers all or a portion of the ions it holdsto the electrochromic layer causing the optical transition in theelectrochromic layer. In some such implementations, for example, whenthe counter electrode layer is formed from NiWO, the counter electrodelayer also optically transitions with the loss of ions it hastransferred to the electrochromic layer. When charge is removed from acounter electrode layer made of NiWO (that is, ions are transported fromthe counter electrode layer to the electrochromic layer), the counterelectrode layer will transition in the opposite direction.

Generally, the transition of the electrochromic layer from one opticalstate to another optical state can be caused by reversible ion insertioninto the electrochromic material (for example, by way of intercalation)and a corresponding injection of charge-balancing electrons. In someinstances, some fraction of the ions responsible for the opticaltransition is irreversibly bound up in the electrochromic material. Someor all of the irreversibly bound ions can be used to compensate for“blind charge” in the material. In some implementations, suitable ionsinclude lithium ions (Li+) and hydrogen ions (H+) (i.e., protons). Insome other implementations, other ions can be suitable. Intercalation oflithium ions, for example, into tungsten oxide (WO_(3-y) (0<y≤˜0.3))causes the tungsten oxide to change from a transparent state to a bluestate.

The description below generally focuses on tinting transitions. Oneexample of a tinting transition is a transition from a transparent (or“translucent,” “bleached” or “least tinted”) state to an opaque (or“fully darkened” or “fully tinted”) state. Another example of a tintingtransition is the reverse—a transition from an opaque state to atransparent state. Other examples of tinting transitions includestransitions to and from various intermediate tint states, for example, atransition from a less tinted, lighter or more transparent state to amore tinted, darker or less transparent state, and vice versa. Each ofsuch tint states, and the tinting transitions between them, may becharacterized or described in terms of percent transmission. Forexample, a tinting transition can be described as being from a currentpercent transmission (% T) to a target % T. Conversely, in some otherinstances, each of the tint states and the tinting transitions betweenthem may be characterized or described in terms of percent tinting; forexample, a transition from a current percent tinting to a target percenttinting.

However, although the following description generally focuses on tintstates and tinting transitions between tint states, other optical statesand optical transitions also are achievable in various implementations.As such, where appropriate and unless otherwise indicated, references totint states or tinting transitions also are intended to encompass otheroptical states and optical transitions. In other words, optical statesand optical state transitions also will be referred to herein as tintstates and tint state transitions, respectively, but this is notintended to limit the optical states and state transitions achievable bythe IGUs 302. For example, such other optical states and statetransitions can include states and state transitions associated withvarious colors, intensities of color (for example, from lighter blue todarker blue and vice versa), reflectivity (for example, from lessreflective to more reflective and vice versa), polarization (forexample, from less polarization to more polarization and vice versa),and scattering density (for example, from less scattering to morescattering and vice versa), among others. Similarly, references todevices, control algorithms or processes for controlling tint states,including causing tinting transitions and maintaining tint states, alsoare intended to encompass such other optical transitions and opticalstates. Additionally, controlling the voltage, current or otherelectrical characteristics provided to an optically-switchable device,and the functions or operations associated with such controlling, alsomay be described hereinafter as “driving” the device or the respectiveIGU, whether or not the driving involves a tint state transition or themaintaining of a current tint state.

The ECD 110 generally includes first and second conducting (or“conductive”) layers. For example, the ECD 110 can includes a firsttransparent conductive oxide (TCO) layer 114 adjacent a first surface ofthe EC stack 112 and a second TCO layer 116 adjacent a second surface ofthe EC stack 112. In some implementations, the first TCO layer 114 canbe formed on the second surface S2, the EC stack 112 can be formed onthe first TCO layer 114, and the second TCO layer 116 can be formed onthe EC stack 112. In some implementations, the first and the second TCOlayers 114 and 116 can each be formed of one or more metal oxidesincluding metal oxides doped with one or more metals. For example, somesuitable metal oxides and doped metal oxides can include indium oxide,indium tin oxide (ITO), doped indium oxide, tin oxide, doped tin oxide,fluorinated tin oxide, zinc oxide, aluminum zinc oxide, doped zincoxide, ruthenium oxide and doped ruthenium oxide, among others. Whilesuch materials are referred to as TCOs in this document, the termencompasses non-oxides as well as oxides that are transparent andelectrically conductive such as certain thin film metals and certainnon-metallic materials such as conductive metal nitrides and compositeconductors, among other suitable materials. In some implementations, thefirst and the second TCO layers 114 and 116 are substantiallytransparent at least in the range of wavelengths where electrochromismis exhibited by the EC stack 112. In some implementations, the first andthe second TCO layers 114 and 116 can each be deposited by physicalvapor deposition (PVD) processes including, for example, sputtering. Insome implementations, the first and the second TCO layers 114 and 116can each have a thickness in the range of approximately 0.01 microns(μm) to approximately 1 μm. A transparent conductive material typicallyhas an electronic conductivity significantly greater than that of theelectrochromic material or the counter electrode material.

The first and the second TCO layers 114 and 116 serve to distributeelectrical charge across respective first and second surfaces of the ECstack 112 to apply an electrical potential (voltage) across thethickness of the EC stack 112. For example, a first applied voltage canbe applied to a first one of the TCO layers and a second applied voltagecan be applied to a second one of the TCO layers. In someimplementations, a first busbar 126 distributes the first appliedvoltage to the first TCO layer 114 and a second busbar 128 distributesthe second applied voltage to the second TCO layer 116. In some otherimplementations, one of the first and the second busbars 126 and 128 canground the respective one of the first and the second TCO layers 114 and116. In other implementations the load can be floated with respect tothe two TCOs. In various implementations, to modify one or more opticalproperties of the EC stack 112, and thus cause an optical transition, acontroller can alter one or both of the first and second appliedvoltages to bring about a change in one or both of the magnitude and thepolarity of the effective voltage applied across the EC stack 112.Desirably, the first and the second TCO layers 114 and 116 serve touniformly distribute electrical charge over respective surfaces of theEC stack 112 with relatively little Ohmic potential drop from the outerregions of the respective surfaces to the inner regions of the surfaces.As such, it is generally desirable to minimize the sheet resistance ofthe first and the second TCO layers 114 and 116. In other words, it isgenerally desirable that each of the first and the second TCO layers 114and 116 behaves as a substantially equipotential layer across allportions of the respective layer. In this way, the first and the secondTCO layers 114 and 116 can uniformly apply an electric potential acrossa thickness of the EC stack 112 to effect a uniform optical transitionof the EC stack 112.

In some implementations, each of the first and the second busbars 126and 128 is printed, patterned, or otherwise formed such that it isoriented along a length of the first pane 104 along at least one borderof the EC stack 112. For example, each of the first and the secondbusbars 126 and 128 can be formed by depositing a conductive ink, suchas a silver ink, in the form of a line. In some implementations, each ofthe first and the second busbars 126 and 128 extends along the entirelength (or nearly the entire length) of the first pane 104, and in someimplementations, along more than one edge of the EC stack 112.

In some implementations, the first TCO layer 114, the EC stack 112 andthe second TCO layer 116 do not extend to the edges of the first pane104. For example, a laser edge delete (LED) or other operation can beused to remove portions of the first TCO layer 114, the EC stack 112 andthe second TCO layer 116 such that these layers are separated or insetfrom the respective edges of the first pane 104 by a distance “G,” whichcan be in the range of approximately 8 mm to approximately 10 mm(although other distances are possible and may be desirable).Additionally, in some implementations, an edge portion of the EC stack112 and the second TCO layer 116 along one side of the first pane 104 isremoved to enable the first busbar 126 to be formed on the first TCOlayer 114 to enable conductive coupling between the first busbar 126 andthe first TCO layer 114. The second busbar 128 is formed on the secondTCO layer 116 to enable conductive coupling between the second busbar128 and the second TCO layer 116. In some implementations, the first andthe second busbars 126 and 128 are formed in a region between spacer 118and the first pane 104 as shown in FIG. 1. For example, each of thefirst and the second busbars 126 and 128 can be inset from an inner edgeof spacer 118 by at least a distance “F,” which can be in the range ofapproximately 2 mm to approximately 3 mm (although other distances arepossible and may be desirable). This arrangement can be advantageous fora number of reasons including, for example, to hide the busbars fromview.

As noted above, the usage of the IGU convention is for convenience only.Indeed, in some implementations the basic unit of an electrochromicwindow can be defined as a pane or substrate of transparent material,upon which an ECD is formed or otherwise arranged, and to whichassociated electrical connections are coupled (to drive the ECD). Assuch, references to an IGU in the following description do notnecessarily include all of the components described with reference tothe IGU 100 of FIG. 1.

Example Control Profile for Driving Optical Transitions

FIG. 2 illustrates an example control profile 200 in accordance withsome implementations. The control profile 200 can be used to drive atransition in an optically-switchable device, such as the ECD 110described above. In some implementations, a window controller can beused to generate and apply the control profile 200 to drive an ECD froma first optical state (for example, a transparent state or a firstintermediate state) to a second optical state (for example, a fullytinted state or a more tinted intermediate state). To drive the ECD inthe reverse direction—from a more tinted state to a less tintedstate—the window controller can apply a similar but inverted profile.For example, the control profile for driving the ECD from the secondoptical state to the first optical state can be a mirror image of thevoltage control profile depicted in FIG. 2. In some otherimplementations, the control profiles for tinting and lightening can beasymmetric. For example, transitioning from a first more tinted state toa second less tinted state can in some instances require more time thanthe reverse; that is, transitioning from the second less tinted state tothe first more tinted state. In some other instances, the reverse may betrue; that is, transitioning from the second less tinted state to thefirst more tinted state can require more time. In other words, by virtueof the device architecture and materials, bleaching or lightening is notnecessarily simply the reverse of coloring or tinting. Indeed, ECDsoften behave differently for each transition due to differences indriving forces for ion intercalation and deintercalation to and from theelectrochromic materials.

In some implementations, the control profile 200 is a voltage controlprofile implemented by varying a voltage provided to the ECD. Forexample, the solid line in FIG. 2 represents an effective voltageV_(Eff) applied across the ECD over the course of a tinting transitionand a subsequent maintenance period. In other words, the solid line canrepresent the relative difference in the electrical voltages V_(App1)and V_(App2) applied to the two conducting layers of the ECD (forexample, the first and the second TCO layers 114 and 116 of the ECD110). The dotted line in FIG. 2 represents a corresponding current (I)through the device. In the illustrated example, the voltage controlprofile 200 includes four stages: a ramp-to-drive stage 202 thatinitiates the transition, a drive stage that continues to drive thetransition, a ramp-to-hold stage, and subsequent hold stage.

The ramp-to-drive stage 202 is characterized by the application of avoltage ramp that increases in magnitude from an initial value at timeto to a maximum driving value of V_(Drive) at time t₁. In someimplementations, the ramp-to-drive stage 202 can be defined by threedrive parameters known or set by the window controller: the initialvoltage at to (the current voltage across the ECD at the start of thetransition), the magnitude of V_(Drive) (governing the ending opticalstate), and the time duration during which the ramp is applied(dictating the speed of the transition). Additionally or alternatively,the window controller also can set a target ramp rate, a maximum ramprate or a type of ramp (for example, a linear ramp, a second degree rampor an n^(th)-degree ramp). In some applications, the ramp rate can belimited to avoid damaging the ECD.

The drive stage 204 is characterized by the application of a constantvoltage V_(Drive) starting at time t₁ and ending at time t₂, at whichpoint the ending optical state is reached (or approximately reached).The ramp-to-hold stage 206 is characterized by the application of avoltage ramp that decreases in magnitude from the drive value V_(Drive)at time t₂ to a minimum holding value of V_(Hold) at time t₃. In someimplementations, the ramp-to-hold stage 206 can be defined by threedrive parameters known or set by the window controller: the drivevoltage V_(Drive), the holding voltage V_(Hold), and the time durationduring which the ramp is applied. Additionally or alternatively, thewindow controller also can set a ramp rate or a type of ramp (forexample, a linear ramp, a second degree ramp or an n^(th)-degree ramp).

The hold stage 208 is characterized by the application of a constantvoltage V_(Hold) starting at time t₃. The holding voltage V_(Hold) isused to maintain the ECD at the ending optical state. As such, theduration of the application of the holding voltage V_(hold) may beconcomitant with the duration of time that the ECD is to be held in theending optical state. For example, because of non-idealities associatedwith the ECD, a leakage current I_(Leak) can result in the slow drainageof electrical charge from the ECD. Such a drainage of electrical chargecan result in a corresponding reversal of ions across the ECD, andconsequently, a slow reversal of the optical transition. In suchapplications, the holding voltage V_(Hold) can be continuously appliedto counter or prevent the leakage current. In some otherimplementations, the holding voltage V_(Hold) can be appliedperiodically to “refresh” the desired optical state, or in other words,to bring the ECD back to the desired optical state.

The voltage control profile 200 illustrated and described with referenceto FIG. 2 is only one example of a voltage control profile suitable forsome implementations. However, many other profiles may be desirable orsuitable in such implementations or in various other implementations orapplications. These other profiles also can readily be achieved usingthe controllers and optically-switchable devices disclosed herein. Forexample, in some implementations, a current profile can be appliedinstead of a voltage profile. In some such instances, a current controlprofile similar to that of the current density shown in FIG. 2 can beapplied. In some other implementations, a control profile can have morethan four stages. For example, a voltage control profile can include oneor more overdrive stages. In one example implementation, the voltageramp applied during the first stage 202 can increase in magnitude beyondthe drive voltage V _(Drive) to an overdrive voltage V_(OD). In somesuch implementations, the first stage 202 can be followed by a rampstage 203 during which the applied voltage decreases from the overdrivevoltage V_(OD) to the drive voltage V_(OD). In some other suchimplementations, the overdrive voltage V_(OD) can be applied for arelatively short time duration before the ramp back down to the drivevoltage V_(Drive).

Additionally, in some implementations, the applied voltage or currentprofiles can be interrupted for relatively short durations of time toprovide open circuit conditions across the device. While such opencircuit conditions are in effect, an actual voltage or other electricalcharacteristics can be measured, detected or otherwise determined tomonitor how far along an optical transition has progressed, and in someinstances, to determine whether changes in the profile are desirable.Such open circuit conditions also can be provided during a hold stage todetermine whether a holding voltage V_(Hold) should be applied orwhether a magnitude of the holding voltage V_(Hold) should be changed.Additional information related to driving and monitoring an opticaltransition is provided in PCT Patent Application No. PCT/US14/43514filed Jun. 20, 2014 and titled CONTROLLING TRANSITIONS IN OPTICALLYSWITCHABLE DEVICES, which is hereby incorporated by reference in itsentirety and for all purposes.

Example Controller Network Architecture

In many instances, optically-switchable windows can form or occupysubstantial portions of a building envelope. For example, theoptically-switchable windows can form substantial portions of the walls,facades and even roofs of a corporate office building, other commercialbuilding or a residential building. In various implementations, adistributed network of controllers can be used to control theoptically-switchable windows. FIG. 3 shows a block diagram of an examplenetwork system, 300, operable to control a plurality of IGUs 302 inaccordance with some implementations. For example, each of the IGUs 302can be the same or similar to the IGU 100 described above with referenceto FIG. 1. One primary function of the network system 300 is controllingthe optical states of the ECDs (or other optically-switchable devices)within the IGUs 302. In some implementations, one or more of the windows302 can be multi-zoned windows, for example, where each window includestwo or more independently controllable ECDs or zones. In variousimplementations, the network system 300 is operable to control theelectrical characteristics of the power signals provided to the IGUs302. For example, the network system 300 can generate and communicatetinting instructions (also referred to herein as “tint commands”) tocontrol voltages applied to the ECDs within the IGUs 302.

In some implementations, another function of the network system 300 isto acquire status information from the IGUs 302 (hereinafter“information” is used interchangeably with “data”). For example, thestatus information for a given IGU can include an identification of, orinformation about, a current tint state of the ECD(s) within the IGU.The network system 300 also can be operable to acquire data from varioussensors, such as temperature sensors, photosensors (also referred toherein as light sensors), humidity sensors, air flow sensors, oroccupancy sensors, whether integrated on or within the IGUs 302 orlocated at various other positions in, on or around the building.

The network system 300 can include any suitable number of distributedcontrollers having various capabilities or functions. In someimplementations, the functions and arrangements of the variouscontrollers are defined hierarchically. For example, the network system300 includes a plurality of distributed window controllers (WCs) 304, aplurality of network controllers (NCs) 306, and a master controller (MC)308. In some implementations, the MC 308 can communicate with andcontrol tens or hundreds of NCs 306. In various implementations, the MC308 issues high level instructions to the NCs 306 over one or more wiredor wireless links 316 (hereinafter collectively referred to as “link316”). The instructions can include, for example, tint commands forcausing transitions in the optical states of the IGUs 302 controlled bythe respective NCs 306. Each NC 306 can, in turn, communicate with andcontrol a number of WCs 304 over one or more wired or wireless links 314(hereinafter collectively referred to as “link 314”). For example, eachNC 306 can control tens or hundreds of the WCs 304. Each WC 304 can, inturn, communicate with, drive or otherwise control one or morerespective IGUs 302 over one or more wired or wireless links 312(hereinafter collectively referred to as “link 312”).

The MC 308 can issue communications including tint commands, statusrequest commands, data (for example, sensor data) request commands orother instructions. In some implementations, the MC 308 can issue suchcommunications periodically, at certain predefined times of day (whichmay change based on the day of week or year), or based on the detectionof particular events, conditions or combinations of events or conditions(for example, as determined by acquired sensor data or based on thereceipt of a request initiated by a user or by an application or acombination of such sensor data and such a request). In someimplementations, when the MC 308 determines to cause a tint state changein a set of one or more IGUs 302, the MC 308 generates or selects a tintvalue corresponding to the desired tint state. In some implementations,the set of IGUs 302 is associated with a first protocol identifier (ID)(for example, a BACnet ID). The MC 308 then generates and transmits acommunication—referred to herein as a “primary tint command”—includingthe tint value and the first protocol ID over the link 316 via a firstcommunication protocol (for example, a BACnet compatible protocol). Insome implementations, the MC 308 addresses the primary tint command tothe particular NC 306 that controls the particular one or more WCs 304that, in turn, control the set of IGUs 302 to be transitioned.

The NC 306 receives the primary tint command including the tint valueand the first protocol ID and maps the first protocol ID to one or moresecond protocol IDs. In some implementations, each of the secondprotocol IDs identifies a corresponding one of the WCs 304. The NC 306subsequently transmits a secondary tint command including the tint valueto each of the identified WCs 304 over the link 314 via a secondcommunication protocol. In some implementations, each of the WCs 304that receives the secondary tint command then selects a voltage orcurrent profile from an internal memory based on the tint value to driveits respectively connected IGUs 302 to a tint state consistent with thetint value. Each of the WCs 304 then generates and provides voltage orcurrent signals over the link 312 to its respectively connected IGUs 302to apply the voltage or current profile.

In some implementations, the various IGUs 302 can be advantageouslygrouped into zones of EC windows, each of which zones includes a subsetof the IGUs 302. In some implementations, each zone of IGUs 302 iscontrolled by one or more respective NCs 306 and one or more respectiveWCs 304 controlled by these NCs 306. In some more specificimplementations, each zone can be controlled by a single NC 306 and twoor more WCs 304 controlled by the single NC 306. Said another way, azone can represent a logical grouping of the IGUs 302. For example, eachzone may correspond to a set of IGUs 302 in a specific location or areaof the building that are driven together based on their location. As amore specific example, consider a building having four faces or sides: aNorth face, a South face, an East Face and a West Face. Consider alsothat the building has ten floors. In such a didactic example, each zonecan correspond to the set of electrochromic windows 100 on a particularfloor and on a particular one of the four faces. Additionally oralternatively, each zone may correspond to a set of IGUs 302 that shareone or more physical characteristics (for example, device parameterssuch as size or age). In some other implementations, a zone of IGUs 302can be grouped based on one or more non-physical characteristics suchas, for example, a security designation or a business hierarchy (forexample, IGUs 302 bounding managers' offices can be grouped in one ormore zones while IGUs 302 bounding non-managers' offices can be groupedin one or more different zones).

In some such implementations, each NC 306 can address all of the IGUs302 in each of one or more respective zones. For example, the MC 308 canissue a primary tint command to the NC 306 that controls a target zone.The primary tint command can include an abstract identification of thetarget zone (hereinafter also referred to as a “zone ID”). In some suchimplementations, the zone ID can be a first protocol ID such as thatjust described in the example above. In such cases, the NC 306 receivesthe primary tint command including the tint value and the zone ID andmaps the zone ID to the second protocol IDs associated with the WCs 304within the zone. In some other implementations, the zone ID can be ahigher level abstraction than the first protocol IDs. In such cases, theNC 306 can first map the zone ID to one or more first protocol IDs, andsubsequently map the first protocol IDs to the second protocol IDs.

User or Third Party Interaction with Network

In some implementations, the MC 308 is coupled to one or moreoutward-facing networks, 310, (hereinafter collectively referred to as“the outward-facing network 310”) via one or more wired or wirelesslinks 318 (hereinafter “link 318”). In some such implementations, the MC308 can communicate acquired status information or sensor data to remotecomputers, mobile devices, servers, databases in or accessible by theoutward-facing network 310. In some implementations, variousapplications, including third party applications or cloud-basedapplications, executing within such remote devices can access data fromor provide data to the MC 308. In some implementations, authorized usersor applications can communicate requests to modify the tint states ofvarious IGUs 302 to the MC 308 via the network 310. In someimplementations, the MC 308 can first determine whether to grant therequest (for example, based on power considerations or based on whetherthe user has the appropriate authorization) prior to issuing a tintcommand. The MC 308 can then calculate, determine, select or otherwisegenerate a tint value and transmit the tint value in a primary tintcommand to cause the tint state transitions in the associated IGUs 302.

For example, a user can submit such a request from a computing device,such as a desktop computer, laptop computer, tablet computer or mobiledevice (for example, a smartphone). In some such implementations, theuser's computing device can execute a client-side application that iscapable of communicating with the MC 308, and in some instances, with amaster controller application executing within the MC 308. In some otherimplementations, the client-side application can communicate with aseparate application, in the same or a different physical device orsystem as the MC 308, which then communicates with the master controllerapplication to effect the desired tint state modifications. In someimplementations, the master controller application or other separateapplication can be used to authenticate the user to authorize requestssubmitted by the user. In some implementations, the user can select theIGUs 302 to be tinted, and inform the MC 308 of the selections, byentering a room number via the client-side application.

Additionally or alternatively, in some implementations, a user's mobiledevice or other computing device can communicate wirelessly with variousWCs 304. For example, a client-side application executing within auser's mobile device can transmit wireless communications including tintstate control signals to a WC 304 to control the tint states of therespective IGUs 302 connected to the WC 304. For example, the user canuse the client-side application to maintain or modify the tint states ofthe IGUs 302 adjoining a room occupied by the user (or to be occupied bythe user or others at a future time). Such wireless communications canbe generated, formatted or transmitted using various wireless networktopologies and protocols (described in more detail below with referenceto the WC 600 of FIG. 6).

In some such implementations, the control signals sent to the respectiveWC 304 from the user's mobile device (or other computing device) canoverride a tint value previously received by the WC 304 from therespective NC 306. In other words, the WC 304 can provide the appliedvoltages to the IGUs 302 based on the control signals from the user'scomputing device rather than based on the tint value. For example, acontrol algorithm or rule set stored in and executed by the WC 304 candictate that one or more control signals from an authorized user'scomputing device take precedence over a tint value received from the NC306. In some other instances, such as in high demand cases, controlsignals such as a tint value from the NC 306 may take precedence overany control signals received by the WC 304 from a user's computingdevice. In some other instances, a control algorithm or rule set maydictate that tint overrides from only certain users or groups or classesof users may take precedence based on permissions granted to such users,as well as in some instances, other factors including time of day or thelocation of the IGUs 302.

In some implementations, based on the receipt of a control signal froman authorized user's computing device, the MC 308 can use informationabout a combination of known parameters to calculate, determine, selector otherwise generate a tint value that provides lighting conditionsdesirable for a typical user, while in some instances also using powerefficiently. In some other implementations, the MC 308 can determine thetint value based on preset preferences defined by or for the particularuser that requested the tint state change via the computing device. Forexample, the user may be required to enter a password or otherwise loginor obtain authorization to request a tint state change. In suchinstances, the MC 308 can determine the identity of the user based on apassword, a security token or based on an identifier of the particularmobile device or other computing device. After determining the user'sidentity, the MC 308 can then retrieve preset preferences for the user,and use the preset preferences alone or in combination with otherparameters (such as power considerations or information from varioussensors) to generate and transmit a tint value for use in tinting therespective IGUs 302.

Wall Devices

In some implementations, the network system 300 also can include wallswitches, dimmers or other tint-state-controlling devices. A wall switchgenerally refers to an electromechanical interface connected to a WC.The wall switch can convey a tint command to the WC, which can thenconvey the tint command to the NC. Such devices also are hereinaftercollectively referred to as “wall devices,” although such devices neednot be limited to wall-mounted implementations (for example, suchdevices also can be located on a ceiling or floor, or integrated on orwithin a desk or a conference table). For example, some or all of theoffices, conference rooms or other rooms of the building can includesuch a wall device for use in controlling the tint states of theadjoining IGUs 302. For example, the IGUs 302 adjoining a particularroom can be grouped into a zone. Each of the wall devices can beoperated by an end user (for example, an occupant of the respectiveroom) to control the tint state or other functions or parameters of theIGUs 302 that adjoin the room. For example, at certain times of the day,the adjoining IGUs 302 may be tinted to a dark state to reduce theamount of light energy entering the room from the outside (for example,to reduce AC cooling requirements). Now suppose that a user desires touse the room. In various implementations, the user can operate the walldevice to communicate control signals to cause a tint state transitionfrom the dark state to a lighter tint state.

In some implementations, each wall device can include one or moreswitches, buttons, dimmers, dials or other physical user interfacecontrols enabling the user to select a particular tint state or toincrease or decrease a current tinting level of the IGUs 302 adjoiningthe room. Additionally or alternatively, the wall device can include adisplay having a touchscreen interface enabling the user to select aparticular tint state (for example, by selecting a virtual button,selecting from a dropdown menu or by entering a tint level or tintingpercentage) or to modify the tint state (for example, by selecting a“darken” virtual button, a “lighten” virtual button, or by turning avirtual dial or sliding a virtual bar). In some other implementations,the wall device can include a docking interface enabling a user tophysically and communicatively dock a portable device such as asmartphone, multimedia device, tablet computer or other portablecomputing device (for example, an IPHONE, IPOD or IPAD produced byApple, Inc. of Cupertino, Calif.). In such implementations, the user cancontrol the tinting levels via input to the portable device, which isthen received by the wall device through the docking interface andsubsequently communicated to the MC 308, NC 306 or WC 304. In suchimplementations, the portable device may include an application forcommunicating with an API presented by the wall device.

For example, the wall device can transmit a request for a tint statechange to the MC 308. In some implementations, the MC 308 can firstdetermine whether to grant the request (for example, based on powerconsiderations or based on whether the user has the appropriateauthorizations/permissions). The MC 308 can then calculate, determine,select or otherwise generate a tint value and transmit the tint value ina primary tint command to cause the tint state transitions in theadjoining IGUs 302. In some such implementations, each wall device canbe connected with the MC 308 via one or more wired links (for example,over communication lines such as CAN or Ethernet compliant lines or overpower lines using power line communication techniques). In some otherimplementations, each wall device can be connected with the MC 308 viaone or more wireless links. In some other implementations, the walldevice can be connected (via one or more wired or wireless connections)with an outward-facing network 310 such as a customer-facing network,which then communicates with the MC 308 via link 318.

In some implementations, the MC 308 can identify the IGUs 302 associatedwith the wall device based on previously programmed or discoveredinformation associating the wall device with the IGUs 302. In someimplementations, a control algorithm or rule set stored in and executedby the MC 308 can dictate that one or more control signals from a walldevice take precedence over a tint value previously generated by the MC308. In some other instances, such as in times of high demand (forexample, high power demand), a control algorithm or rule set stored inand executed by the MC 308 can dictate that the tint value previouslygenerated by the MC 308 takes precedence over any control signalsreceived from a wall device.

In some other implementations or instances, based on the receipt of atint-state-change request or control signal from a wall device, the MC308 can use information about a combination of known parameters togenerate a tint value that provides lighting conditions desirable for atypical user, while in some instances also using power efficiently. Insome other implementations, the MC 308 can generate the tint value basedon preset preferences defined by or for the particular user thatrequested the tint state change via the wall device. For example, theuser may be required to enter a password into the wall device or to usea security token or security fob such as the IBUTTON or other 1-Wiredevice to gain access to the wall device. In such instances, the MC 308can determine the identity of the user, based on the password, securitytoken or security fob, retrieve preset preferences for the user, and usethe preset preferences alone or in combination with other parameters(such as power considerations or information from various sensors) tocalculate, determine, select or otherwise generate a tint value for therespective IGUs 302.

In some other implementations, the wall device can transmit a tint statechange request to the appropriate NC 306, which then communicates therequest, or a communication based on the request, to the MC 308. Forexample, each wall device can be connected with a corresponding NC 306via one or more wired links such as those just described for the MC 308or via a wireless link (such as those described below). In some otherimplementations, the wall device can transmit a request to theappropriate NC 306, which then itself determines whether to override aprimary tint command previously received from the MC 308 or a primary orsecondary tint command previously generated by the NC 306 (as describedbelow, the NC 306 can in some implementations generate tint commandswithout first receiving a tint command from an MC 308). In some otherimplementations, the wall device can communicate requests or controlsignals directly to the WC 304 that controls the adjoining IGUs 302. Forexample, each wall device can be connected with a corresponding WC 304via one or more wired links such as those just described for the MC 308or via a wireless link (such as those described below with reference tothe WC 600 of FIG. 6).

In some specific implementations, the NC 306 or the MC 308 determineswhether the control signals from the wall device should take priorityover a tint value previously generated by the NC 306 or the MC 308. Asdescribed above, in some implementations, the wall device cancommunicate directly with the NC 306. However, in some otherimplementations, the wall device can communicate requests directly tothe MC 308 or directly to a WC 304, which then communicates the requestto the NC 306. In still other implementations, the wall device cancommunicate requests to a customer-facing network (such as a networkmanaged by the owners or operators of the building), which then passesthe requests (or requests based therefrom) to the NC 306 either directlyor indirectly by way of the MC 308. In some implementations, a controlalgorithm or rule set stored in and executed by the NC 306 or the MC 308can dictate that one or more control signals from a wall device takeprecedence over a tint value previously generated by the NC 306 or theMC 308. In some other instances, such as in times of high demand (forexample, high power demand), a control algorithm or rule set stored inand executed by the NC 306 or the MC 308 can dictate that the tint valuepreviously generated by the NC 306 or the MC 308 takes precedence overany control signals received from a wall device.

As described above with reference to the MC 308, in some otherimplementations, based on the receipt of a tint-state-change request orcontrol signal from a wall device, the NC 306 can use information abouta combination of known parameters to generate a tint value that provideslighting conditions desirable for a typical user, while in someinstances also using power efficiently. In some other implementations,the NC 306 or the MC 308 can generate the tint value based on presetpreferences defined by or for the particular user that requested thetint state change via the wall device. As described above with referenceto the MC 308, the user may be required to enter a password into thewall device or to use a security token or security fob such as theIBUTTON or other 1-Wire device to gain access to the wall device. Insuch instances, the NC 306 can communicate with the MC 308 to determinethe identity of the user, or the MC 308 can alone determine the identityof the user, based on the password, security token or security fob,retrieve preset preferences for the user, and use the preset preferencesalone or in combination with other parameters (such as powerconsiderations or information from various sensors) to calculate,determine, select or otherwise generate a tint value for the respectiveIGUs 302.

In some implementations, the MC 308 is coupled to an external database(or “data store” or “data warehouse”) 320. In some implementations, thedatabase 320 can be a local database coupled with the MC 308 via a wiredhardware link 322. In some other implementations, the database 320 canbe a remote database or a cloud-based database accessible by the MC 308via an internal private network or over the outward-facing network 310.In some implementations, other computing devices, systems or serversalso can have access to read the data stored in the database 320, forexample, over the outward-facing network 310. Additionally, in someimplementations, one or more control applications or third partyapplications also can have access to read the data stored in thedatabase via the outward-facing network 310. In some cases, the MC 308stores in the database 320 a record of all tint commands including thecorresponding tint values issued by the MC 308. The MC 308 also cancollect status and sensor data and store it in the database 320. In suchinstances, the WCs 304 can collect the sensor data and status data fromthe IGUs 302 and communicate the sensor data and status data to therespective NCs 306 over link 314 for communication to the MC 308 overlink 316. Additionally or alternatively, the NCs 306 or the MC 308themselves also can be connected to various sensors such as light,temperature or occupancy sensors within the building as well as light ortemperature sensors positioned on, around or otherwise external to thebuilding (for example, on a roof of the building). In someimplementations the NCs 306 or the WCs 304 also can transmit status orsensor data directly to the database 320 for storage.

Integration with Other Systems or Services

In some implementations, the network system 300 also can be designed tofunction in conjunction with modern heating, ventilation, and airconditioning (HVAC) systems, interior lighting systems, security systemsor power systems as an integrated and efficient energy control systemfor an entire building or a campus of buildings. Some implementations ofthe network system 300 are suited for integration with a buildingmanagement system (BMS), 324. A BMS is broadly a computer-based controlsystem that can be installed in a building to monitor and control thebuilding's mechanical and electrical equipment such as HVAC systems(including furnaces or other heaters, air conditioners, blowers andvents), lighting systems, power systems, elevators, fire systems, andsecurity systems. The BMS can include hardware and associated firmwareand software for maintaining conditions in the building according topreferences set by the occupants or by a building manager or otheradministrator. The software can be based on, for example, internetprotocols or open standards. A BMS can typically be used in largebuildings where it functions to control the environment within thebuilding. For example, the BMS can control lighting, temperature, carbondioxide levels, and humidity within the building. To control thebuilding environment, the BMS can turn on and off various mechanical andelectrical devices according to rules or in response to conditions. Suchrules and conditions can be selected or specified by a building manageror administrator, for example. One function of a BMS can be to maintaina comfortable environment for the occupants of a building whileminimizing heating and cooling energy losses and costs. In someimplementations, the BMS can be configured not only to monitor andcontrol, but also to optimize the synergy between various systems, forexample, to conserve energy and lower building operation costs.

Additionally or alternatively, some implementations of the networksystem 300 are suited for integration with a smart thermostat service,alert service (for example, fire detection), security service or otherappliance automation service. On example of a home automation service isNEST®, made by Nest Labs of Palo Alto, Calif., (NEST® is a registeredtrademark of Google, Inc. of Mountain View, Calif.). As used herein,references to a BMS can in some implementations also encompass, or bereplaced with, such other automation services.

In some implementations, the MC 308 and a separate automation service,such as a BMS 324, can communicate via an application programminginterface (API). For example, the API can execute in conjunction with amaster controller application (or platform) within the MC 308, or inconjunction with a building management application (or platform) withinthe BMS 324. The MC 308 and the BMS 324 can communicate over one or morewired links 326 or via the outward-facing network 310. In someinstances, the BMS 324 can communicate instructions for controlling theIGUs 302 to the MC 308, which then generates and transmits primary tintcommands to the appropriate NCs 306. In some implementations, the NCs306 or the WCs 304 also can communicate directly with the BMS 324(whether through a wired/hardware link or wirelessly through a wirelessdata link). In some implementations, the BMS 324 also can receive data,such as sensor data, status data and associated timestamp data,collected by one or more of the MC 308, the NCs 306 and the WCs 304. Forexample, the MC 308 can publish such data over the network 310. In someother implementations in which such data is stored in a database 320,the BMS 324 can have access to some or all of the data stored in thedatabase 320.

Example Master Controller

FIG. 4 shows a block diagram of an example master controller (MC) 400 inaccordance with some implementations. For example, the MC 400 of FIG. 4can be used to implement the MC 308 described above with reference tothe network system 300 of FIG. 3. As used herein, references to “the MC400” also encompass the MC 308, and vice versa; in other words, the tworeferences may be used interchangeably. The MC 400 can be implemented inor as one or more computers, computing devices or computer systems(herein used interchangeably where appropriate unless otherwiseindicated). Additionally, reference to “the MC 400” collectively refersto any suitable combination of hardware, firmware and software forimplementing the functions, operations, processes or capabilitiesdescribed. For example, the MC 400 can refer to a computer thatimplements a master controller application (also referred to herein as a“program” or a “task”).

As shown in FIG. 4, the MC 400 generally includes one or more processors402 (also collectively referred to hereinafter as “the processor 402”).Processor 402 can be or can include a central processing unit (CPU),such as a single core or a multi-core processor. The processor 402 canadditionally include a digital signal processor (DSP) or a networkprocessor in some implementations. In some implementations, theprocessor 402 also can include one or more application-specificintegrated circuits (ASICs). The processor 402 is coupled with a primarymemory 404, a secondary memory 406, an inward-facing network interface408 and an outward-facing network interface 410. The primary memory 404can include one or more high-speed memory devices such as, for example,one or more random-access memory (RAM) devices including dynamic-RAM(DRAM) devices. Such DRAM devices can include, for example, synchronousDRAM (SDRAM) devices and double data rate SDRAM (DDR SDRAM) devices(including DDR2 SDRAM, DDR3 SDRAM, and DDR4 SDRAM), thyristor RAM(T-RAM), and zero-capacitor (Z-RAM®), among other suitable memorydevices.

The secondary memory 406 can include one or more hard disk drives (HDDs)or one or more solid-state drives (SSDs). In some implementations, thememory 406 can store processor-executable code (or “programminginstructions”) for implementing a multi-tasking operating system suchas, for example, an operating system based on a Linux® kernel. In someother implementations, the operating system can be a UNIX®- orUnix-like-based operating system, a Microsoft Windows®-based operatingsystem, or another suitable operating system. The memory 406 also canstore code executable by the processor 402 to implement the mastercontroller application described above, as well as code for implementingother applications or programs. The memory 406 also can store statusinformation, sensor data or other data collected from networkcontrollers, window controllers and various sensors.

In some implementations, the MC 400 is a “headless” system; that is, acomputer that does not include a display monitor or other user inputdevice. In some such implementations, an administrator or otherauthorized user can log in to or otherwise access the MC 400 from aremote computer or mobile computing device over a network (for example,the network 310) to access and retrieve information stored in the MC400, to write or otherwise store data in the MC 400, and to controlvarious functions, operations, processes or parameters implemented orused by the MC 400. In some other implementations, the MC 400 also caninclude a display monitor and a direct user input device (for example,one or more of a mouse, a keyboard and a touchscreen).

In various implementations, the inward-facing network interface 408enables the MC 400 to communicate with various distributed controllers,and in some implementations, also with various sensors. Theinward-facing network interface 408 can collectively refer to one ormore wired network interfaces or one or more wireless network interfaces(including one or more radio transceivers). In the context of thenetwork system 300 of FIG. 3, the MC 400 can implement the MC 308 andthe inward-facing network interface 408 can enable communication withthe downstream NCs 306 over the link 316.

The outward-facing network interface 410 enables the MC 400 tocommunicate with various computers, mobile devices, servers, databasesor cloud-based database systems over one or more networks. Theoutward-facing network interface 410 also can collectively refer to oneor more wired network interfaces or one or more wireless networkinterfaces (including one or more radio transceivers). In the context ofthe network system 300 of FIG. 3, the outward-facing network interface410 can enable communication with various computers, mobile devices,servers, databases or cloud-based database systems accessible via theoutward-facing network 310 over the link 318. As described above, insome implementations, the various applications, including third partyapplications or cloud-based applications, executing within such remotedevices can access data from or provide data to the MC 400 or to thedatabase 320 via the MC 400. In some implementations, the MC 400includes one or more APIs for facilitating communication between the MC400 and various third party applications. Some example implementationsof APIs that the MC 400 can enable are described in PCT PatentApplication No. PCT/US15/64555 (Attorney Docket No. VIEWP073WO) filedDec. 8, 2015 and titled MULTIPLE INTERACTING SYSTEMS AT A SITE, which ishereby incorporated by reference in its entirety and for all purposes.For example, such third party applications can include variousmonitoring services including thermostat services, alert services (forexample, fire detection), security services or other applianceautomation services. Additional examples of monitoring services andsystems can be found in PCT Patent Application No. PCT/US2015/019031(Attorney Docket No. VIEWP061WO) filed Mar. 5, 2015 and titledMONITORING SITES CONTAINING SWITCHABLE OPTICAL DEVICES AND CONTROLLERS,which is hereby incorporated by reference in its entirety and for allpurposes.

In some implementations, one or both of the inward-facing networkinterface 408 and the outward-facing network interface 410 can include aBACnet compatible interface. BACnet is a communications protocoltypically used in building automation and control networks and definedby the ASHRAE/ANSI 135 and ISO 16484-5 standards. The BACnet protocolbroadly provides mechanisms for computerized building automation systemsand devices to exchange information, regardless of the particularservices they perform. For example, BACnet has traditionally been usedto enable communication among heating, ventilating, and air-conditioningcontrol (HVAC) systems, lighting control systems, access or securitycontrol systems, and fire detection systems as well as their associatedequipment. In some other implementations, one or both of theinward-facing network interface 408 and the outward-facing networkinterface 410 can include an oBIX (Open Building Information Exchange)compatible interface or another RESTful Web Services-based interface. Assuch, while the following description is sometimes focused on BACnetimplementations, in other implementations, other protocols compatiblewith oBIX or other RESTful Web Services can be used.

The BACnet protocol is generally based on a server-client architecture.In some implementations, as viewed from the outward-facing network 310,the MC 400 functions as a BACnet server. For example, the MC 400 canpublish various information through the outward-facing network interface410 over the network 310 to various authorized computers, mobiledevices, servers or databases, or to various authorized applicationsexecuting on such devices. When viewed from the rest of the networksystem 300, the MC 400 can function as a client. In some suchimplementations, the NCs 306 function as BACnet servers collecting andstoring status data, sensor data or other data acquired from the WCs304, and publishing this acquired data such that it is accessible to theMC 400.

The MC 400 can communicate as a client to each of the NCs 306 usingBACnet standard data types. Such BACnet data types can include analogvalues (AVs). In some such implementations, each NC 306 stores an arrayof AVs. The array of AVs can be organized by BACnet IDs. For example,each BACnet ID can be associated with at least two AVs; a first one ofthe AVs can be associated with a tint value set by the MC 400 and asecond one of the AVs can be associated with a status indication valueset (or received) from a respective WC 304. In some implementations,each BACnet ID can be associated with one or more WCs 304. For example,each of the WCs 304 can be identified by a second protocol ID such as aController Area Network (CAN) vehicle bus standard ID (referred tohereinafter as a “CAN ID”). In such implementations, each BACnet ID canbe associated with one or more CAN IDs in the NC 306.

In some implementations, when the MC 400 determines to tint one or moreIGUs 302, the MC 400 writes a specific tint value to the AV in the NC306 associated with the one or more respective WCs 304 that control thetarget IGUs 302. In some more specific implementations, the MC 400generates a primary tint command including a BACnet ID associated withthe WCs 304 that control the target IGUs 302. The primary tint commandalso can include a tint value for the target IGUs 302. The MC 400 candirect the transmission of the primary tint command through theinward-facing interface 408 and to the particular NC 306 using a networkaddress of the NC 306. For example, the network address of the NC 306can include an Internet Protocol (IP) address (for example, an IPv4 orIPv6 address) or a Media Access Control (MAC) address (for example, whencommunicating over an Ethernet link 316).

The MC 400 can calculate, determine, select or otherwise generate a tintvalue for one or more IGUs 302 based on a combination of parameters. Forexample, the combination of parameters can include time or calendarinformation such as the time of day, day of year or time of season.Additionally or alternatively, the combination of parameters can includesolar calendar information such as, for example, the direction of thesun relative to the IGUs 302. In some instances, the direction of thesun relative to the IGUs 302 can be determined by the MC 400 based ontime and calendar information together with information known about thegeographical location of the building on the Earth and the directionthat the IGUs face (for example, in a North-East-Down coordinatesystem). The combination of parameters also can include the outsidetemperature (external to the building), the inside temperature (within aroom adjoining the target IGUs 302), or the temperature within theinterior volume of the IGUs 302. The combination of parameters also caninclude information about the weather (for example, whether it is clear,sunny, overcast, cloudy, raining or snowing). Parameters such as thetime of day, day of year, or direction of the sun can be programmed intoand tracked by the MC 308. Parameters such as the outside temperature,inside temperature or IGU temperature can be obtained from sensors in,on or around the building or sensors integrated on or within the IGUs302. Some information about the weather also can be obtained from suchsensors. Additionally or alternatively, parameters such as the time ofday, time of year, direction of the sun, or weather can be provided by,or determined based on information provided by, various applicationsincluding third party applications over the network 310. Additionalexamples of algorithms, routines, modules, or other means for generatingtint values are described in U.S. patent application Ser. No. 13/722,969(Attorney Docket No. VIEWP049) filed Feb. 21, 2013 and titled CONTROLMETHOD FOR TINTABLE WINDOWS, and in PCT Patent Application No.PCT/2015/029675 (Attorney Docket No. VIEWP049X1WO) filed May 7, 2015 andtitled CONTROL METHOD FOR TINTABLE WINDOWS, both of which are herebyincorporated by reference in their entireties and for all purposes.

Generally, each ECD within each IGU 302 is capable of being tinted,responsive to a suitable driving voltage applied across the EC stack, tovirtually any tint state within a continuous tint spectrum defined bythe material properties of the EC stack. However, in someimplementations, the MC 400 is programmed to select a tint value from afinite number of discrete tint values. For example, the tint values canbe specified as integer values. In some such implementations, the numberof available discrete tint values can be 4, 8, 16, 32, 64, 128 or 256 ormore. For example, a 2-bit binary number can be used to specify any oneof four possible integer tint values, a 3-bit binary number can be usedto specify any one of eight possible integer tint values, a 4-bit binarynumber can be used to specify any one of sixteen possible integer tintvalues, a 5-bit binary number can be used to specify any one ofthirty-two possible integer tint values, and so on. Each tint value canbe associated with a target tint level (for example, expressed as apercentage of maximum tint, maximum safe tint, or maximum desired oravailable tint). For didactic purposes, consider an example in which theMC 400 selects from among four available tint values: 0, 5, 10 and 15(using a 4-bit or higher binary number). The tint values 0, 5, 10 and 15can be respectively associated with target tint levels of 60%, 40%, 20%and 4%, or 60%, 30%, 10% and 1%, or another desired, advantageous, orsuitable set of target tint levels.

Example Network Controller

FIG. 5 shows a block diagram of an example network controller (NC) 500in accordance with some implementations. For example, the NC 500 of FIG.5 can be used to implement the NC 306 described above with reference tothe network system 300 of FIG. 3. As used herein, references to “the NC500” also encompass the NC 306, and vice versa; in other words, the tworeferences may be used interchangeably. The NC 500 can be implemented inor as one or more network components, networking devices, computers,computing devices or computer systems (herein used interchangeably whereappropriate unless otherwise indicated). Additionally, reference to “theNC 500” collectively refers to any suitable combination of hardware,firmware and software for implementing the functions, operations,processes or capabilities described. For example, the NC 500 can referto a computer that implements a network controller application (alsoreferred to herein as a “program” or a “task”).

As shown in FIG. 5, the NC 500 generally includes one or more processors502 (also collectively referred to hereinafter as “the processor 502”).In some implementations, the processor 502 can be implemented as amicrocontroller or as one or more logic devices including one or moreapplication-specific integrated circuits (ASICs) or programmable logicdevices (PLDs), such as field-programmable gate arrays (FPGAs) orcomplex programmable logic devices (CPLDs). If implemented in a PLD, theprocessor can be programmed into the PLD as an intellectual property(IP) block or permanently formed in the PLD as an embedded processorcore. In some other implementations, the processor 502 can be or caninclude a central processing unit (CPU), such as a single core or amulti-core processor. The processor 502 is coupled with a primary memory504, a secondary memory 506, a downstream network interface 508 and anupstream network interface 510. In some implementations, the primarymemory 504 can be integrated with the processor 502, for example, as asystem-on-chip (SOC) package, or in an embedded memory within a PLDitself. In some other implementations, the NC 500 alternatively oradditionally can include one or more high-speed memory devices such as,for example, one or more RAM devices.

The secondary memory 506 can include one or more solid-state drives(SSDs) storing one or more lookup tables or arrays of values. In someimplementations, the secondary memory 506 can store a lookup table thatmaps first protocol IDs (for example, BACnet IDs) received from the MC400 to second protocol IDs (for example, CAN IDs) each identifying arespective one of the WCs 304, and vice versa. In some implementations,the secondary memory 506 can additionally or alternatively store one ormore arrays or tables. In some implementations, such arrays or tablescan be stored as comma-separated values (CSV) files or via anothertable-structured file format. For example, each row of the file can beidentified by a timestamp corresponding to a transaction with a WC 304.Each row can include a tint value (C) for the IGUs 302 controlled by theWC 304 (for example, as set by the MC 400 in the primary tint command);a status value (S) for the IGUs 302 controlled by the WC 304; a setpoint voltage (for example, the effective applied voltage V_(Eff)) anactual voltage level V_(Act) measured, detected or otherwise determinedacross the ECDs within the IGUs 302; an actual current level I_(Act)measured, detected or otherwise determined through the ECDs within theIGUs 302; and various sensor data. In some implementations, each row ofthe CSV file can include such status information for each and all of theWCs 304 controlled by the NC 500. In some such implementations, each rowalso includes the CAN IDs or other IDs associated with each of therespective WC 304.

In some implementations in which the NC 500 is implemented in a computerthat executes a network controller application, the secondary memory 506also can store processor-executable code (or “programming instructions”)for implementing a multi-tasking operating system such as, for example,an operating system based on a Linux® kernel. In some otherimplementations, the operating system can be a UNIX®- or Unix-like-basedoperating system, a Microsoft Windows®-based operating system, oranother suitable operating system. The memory 506 also can store codeexecutable by the processor 502 to implement the network controllerapplication described above, as well as code for implementing otherapplications or programs.

In various implementations, the downstream network interface 508 enablesthe NC 500 to communicate with distributed WCs 304, and in someimplementations, also with various sensors. In the context of thenetwork system 300 of FIG. 3, the NC 500 can implement the NC 306 andthe downstream network interface 508 can enable communication with theWCs 304 over the link 314. The downstream network interface 508 cancollectively refer to one or more wired network interfaces or one ormore wireless network interfaces (including one or more radiotransceivers). In some implementations, the downstream interface 508 caninclude a CANbus interface enabling the NC 500 to distribute commands,requests or other instructions to various WCs 304, and to receiveresponses including status information from the WCs 304, according to aCANBus protocol (for example, via the CANopen communication protocol).In some implementations, a single CANbus interface can enablecommunication between the NC 500 and tens, hundreds or thousands of WCs304. Additionally or alternatively, the downstream interface 508 caninclude one or more Universal Serial Bus (USB) interfaces (or “ports”).In some such implementations, to enable communication via a CANbuscommunication protocol, a USB-to-CAN adapter can be used to couple theUSB port of the downstream interface 508 with CANbus-compatible cables.In some such implementations, to enable the NC 500 to control even moreWCs 304, a USB hub (for example, having 2, 3, 4, 5 10 or more hub ports)can be plugged into the USB port of the downstream interface 508. AUSB-to-CAN adapter can then be plugged into each hub port of the USBhub.

The upstream network interface 510 enables the NC 500 to communicatewith the MC 400, and in some implementations, also with various othercomputers, servers or databases (including the database 320). Theupstream network interface 510 also can collectively refer to one ormore wired network interfaces or one or more wireless network interfaces(including one or more radio transceivers). In the context of thenetwork system 300 of FIG. 3, the upstream network interface 510 canenable communication with the MC 308 over the link 318. In someimplementations, the upstream network interface 510 also can be coupledto communicate with applications, including third party applications andcloud-based applications, over the outward-facing network 310. Forexample, in implementations in which the NC 500 is implemented as anetwork controller application executing as a task within a computer,the network controller application can communicate directly with theoutward-facing network 310 via the operating system and the upstreamnetwork interface 510. In some other implementations, the NC 500 may beimplemented as a task running on the MC 308 and managing the CANbusdevices via the CANbus interface. In such implementations, in additionor as an alternative to TCP/IP or UDP/IP communications to the MC, thecommunications could be via UNIX Domain Sockets (UDS) or othercommunication methods like shared memory, or other non-IP communicationmethods.

In some implementations, the upstream interface 510 can include BACnetcompatible interface, an oBIX compatible interface or another RESTfulWeb Services-based interface. As described above with reference to FIG.4, in some implementations the NC 500 functions as a BACnet servercollecting and storing status data, sensor data or other data acquiredfrom the WCs 304, and publishing this acquired data such that it isaccessible to the MC 400. In some implementations, the NC 500 also canpublish this acquired data over the network 310 directly; that is,without first passing the data to the MC 400. The NC 500 also functionsin some respects similar to a router. For example, the NC 500 canfunction as a BACnet to CANBus gateway, receiving communicationstransmitted from the MC 400 according to the BACnet protocol, convertingcommands or messages from the BACnet protocol to a CANBus protocol (forexample, the CANopen communication protocol), and distributing commandsor other instructions to various WCs 304 according to the CANBusprotocol.

BACnet is built over the user datagram protocol (UDP). In some otherimplementations, a non-broadcast-based communication protocol can beused for communication between the MC 400 and the NCs 500. For example,the transmission control protocol (TCP) can serve as the transport layeras opposed to UDP. In some such implementations, the MC 400 cancommunicate with the NCs 500 via an oBIX-compatible communicationprotocol. In some other implementations, the MC 400 can communicate withthe NCs 500 via a WebSocket-compatible communication protocol. Such TCPprotocols also can allow the NCs 500 to communicate directly with oneanother.

In various implementations, the NC 500 can be configured to performprotocol translation (or “conversion”) between one or more upstreamprotocols and one or more downstream protocols. As described above, theNC 500 can perform translation from BACnet to CANopen, and vice versa.As another example, the NC 500 can receive upstream communications fromthe MC 400 via an oBIX protocol and translate the communications intoCANopen or other CAN-compatible protocols for transmission to thedownstream WCs 304, and vice versa. In some wireless implementations,the NC 500 or the MC 400 also can translate various wireless protocolsincluding, for example, protocols based on the IEEE 802.11 standard (forexample, WiFi), protocols based on the IEEE 802.15.4 standard (forexample, ZigBee, 6LoWPAN, ISA100.11a, WirelessHART or MiWi), protocolsbased on the Bluetooth standard (including the Classic Bluetooth,Bluetooth high speed and Bluetooth low energy protocols and includingthe Bluetooth v4.0, v4.1 and v4.2 versions), or protocols based on theEnOcean standard (ISO/IEC 14543-3-10). For example, the NC 500 canreceive upstream communications from the MC 400 via an oBIX protocol andtranslate the communications into WiFi or 6LowPAN for transmission tothe downstream WCs 304, and vice versa. As another example, the NC 500can receive upstream communications from the MC 400 via WiFi or 6LowPANand translate the communications into CANopen for transmission to thedownstream WCs 304, and vice versa. In some other examples, the MC 400rather than the NC 500 handles such translations for transmission todownstream WCs 304.

As described above with reference to FIG. 4, when the MC 400 determinesto tint one or more IGUs 302, the MC 400 can write a specific tint valueto the AV in the NC 500 associated with the one or more respective WCs304 that control the target IGUs 302. In some implementations, to do so,the MC 400 generates a primary tint command communication including aBACnet ID associated with the WCs 304 that control the target IGUs 302.The primary tint command also can include a tint value for the targetIGUs 302. The MC 400 can direct the transmission of the primary tintcommand to the NC 500 using a network address such as, for example, anIP address or a MAC address. Responsive to receiving such a primary tintcommand from the MC 400 through the upstream interface 510, the NC 500can unpackage the communication, map the BACnet ID (or other firstprotocol ID) in the primary tint command to one or more CAN IDs (orother second protocol IDs), and write the tint value from the primarytint command to a first one of the respective AVs associated with eachof the CAN IDs.

In some implementations, the NC 500 then generates a secondary tintcommand for each of the WCs 304 identified by the CAN IDs. Eachsecondary tint command can be addressed to a respective one of the WCs304 by way of the respective CAN ID. Each secondary tint command alsocan include the tint value extracted from the primary tint command. TheNC 500 transmits the secondary tint commands to the target WCs 304through the downstream interface 508 via a second communication protocol(for example, via the CANOpen protocol). In some implementations, when aWC 304 receives such a secondary tint command, the WC 304 transmits astatus value back to the NC 500 indicating a status of the WC 304. Forexample, the tint status value can represent a “tinting status” or“transition status” indicating that the WC is in the process of tintingthe target IGUs 302, an “active” or “completed” status indicating thatthe target IGUs 302 are at the target tint state or that the transitionhas been finished, or an “error status” indicating an error. After thestatus value has been stored in the NC 500, the NC 500 can publish thestatus information or otherwise make the status information accessibleto the MC 400 or to various other authorized computers or applications.In some other implementations, the MC 400 can request status informationfor a particular WC 304 from the NC 500 based on intelligence, ascheduling policy, or a user override. For example, the intelligence canbe within the MC 400 or within a BMS. A scheduling policy can be storedin the MC 400, another storage location within the network system 300,or within a cloud-based system.

Integrated Master Controller and Network Controller

As described above, in some implementations the MC 400 and the NC 500can be implemented as a master controller application and a networkcontroller application, respectively, executing within respectivephysical computers or other hardware devices. In some alternativeimplementations, each of the master controller application and thenetwork controller application can be implemented within the samephysical hardware. For example, each of the master controllerapplication and the network controller application can be implemented asa separate task executing within a single computer device that includesa multi-tasking operating system such as, for example, an operatingsystem based on a Linux® kernel or another suitable operating system.

In some such integrated implementations, the master controllerapplication and the network controller application can communicate viaan application programming interface (API). In some particularimplementations, the master controller and network controllerapplications can communicate over a loopback interface. By way ofreference, a loopback interface is a virtual network interface,implemented through an operating system, which enables communicationbetween applications executing within the same device. A loopbackinterface is typically identified by an IP address (often in the127.0.0.0/8 address block in IPv4, or the 0:0:0:0:0:0:0:1 address (alsoexpressed as ::1) in IPv6). For example, the master controllerapplication and the network controller application can each beprogrammed to send communications targeted to one another to the IPaddress of the loopback interface. In this way, when the mastercontroller application sends a communication to the network controllerapplication, or vice versa, the communication does not need to leave thecomputer.

In implementations in which the MC 400 and the NC 500 are implemented asmaster controller and network controller applications, respectively,there are generally no restrictions limiting the available protocolssuitable for use in communication between the two applications. Thisgenerally holds true regardless of whether the master controllerapplication and the network controller application are executing astasks within the same or different physical computers. For example,there is no need to use a broadcast communication protocol, such asBACnet, which limits communication to one network segment as defined bya switch or router boundary. For example, the oBIX communicationprotocol can be used in some implementations for communication betweenthe MC 400 and the NCs 500.

In the context of the network system 300, each of the NCs 500 can beimplemented as an instance of a network controller application executingas a task within a respective physical computer. In someimplementations, at least one of the computers executing an instance ofthe network controller application also executes an instance of a mastercontroller application to implement the MC 400. For example, while onlyone instance of the master controller application may be activelyexecuting in the network system 300 at any given time, two or more ofthe computers that execute instances of network controller applicationcan have an instance of the master controller application installed. Inthis way, redundancy is added such that the computer currently executingthe master controller application is no longer a single point of failureof the entire system 300. For example, if the computer executing themaster controller application fails or if that particular instance ofthe master controller application otherwise stops functioning, anotherone of the computers having an instance of the master networkapplication installed can begin executing the master controllerapplication to take over for the other failed instance. In some otherapplications, more than one instance of the master controllerapplication may be executing concurrently. For example, the functions,processes or operations of the master controller application can bedistributed to two (or more) instances of the master controllerapplication.

Example Window Controller

FIG. 6 shows a circuit schematic diagram of an example window controller(WC) 600 in accordance with some implementations. For example, the WC600 of FIG. 6 can be used to implement each one of the WCs 304 describedabove with reference to the network system 300 of FIG. 3. As usedherein, references to “the WC 600” also encompass the WC 304, and viceversa; in other words, the two references may be used interchangeably.As described above, the WC 600 is generally operable and adapted todrive optical state transitions in, or to maintain the optical statesof, one or more coupled optically-switchable devices such as the ECDs110 described above with reference to FIG. 1. In some implementations,the one or more ECDs coupled with the WC 600 are configured withinrespective IGUs 602 (such as the IGU 100 described above with referenceto FIG. 1). The WC 600 also is operable to communicate with the coupledIGUs 602, for example, to read data from or to transfer data to the IGUs602.

The WC 600 broadly includes a processing unit 604. The WC 600 alsobroadly includes a power circuit 606, a drive circuit 608 and a feedbackcircuit 610 (each of which is delineated with a heavy dashed line andgray shading). In the illustrated implementation, the WC 600additionally includes a communications circuit 612. Each of the drivecircuit 608, the power circuit 606, the feedback circuit 610 and thecommunications circuit 612 can include a number of individual circuitcomponents including integrated circuits (ICs). Each of the variouscomponents described in more detail below may be described as being “apart of” a respective one of the aforementioned circuits 606, 608, 610and 612. However, the groupings of components into respective ones ofthe circuits 606, 608, 610 and 612 are in name only and for purposes ofconvenience in facilitating the disclosure of the describedimplementations. As such, the functions, capabilities and limitations ofthe various described components are not intended to be defined by therespective grouping; rather, the functions, abilities and limitations ofeach of the individual components are defined only by those of thecomponents themselves, and by their integration with other components towhich they are electrically connected or coupled.

The WC 600 includes a first upstream interface (or set of interfaces)614 for coupling to an upstream set of cables 616. For example, theupstream set of cables 616 can implement the link 314 described abovewith reference to the network system 300 FIG. 3. In someimplementations, the upstream set of cables 616 includes at least fourlines: two power distribution lines and two communication lines. In somefive-line implementations, the upstream set of cables 616 additionallyincludes a system ground line, such as a building ground or Earth ground(for practical purposes an absolute ground from which all other voltagesin the building can be measured). The upstream interface 614 can includea corresponding number of pins (not shown)—one pin to couple each of thelines in the upstream set of cables 616 into the WC 600. For example, afirst one of the pins can couple a first one of the power distributionlines from the upstream set of cables 616 to a first power supply line622 within the WC 600. A second one of the pins can couple a second oneof the power distribution lines (for example, a power supply return)from the upstream set of cables 616 to a second power supply line 624within the WC 600. A third one of the pins can couple a first one of thecommunication lines from the upstream set of cables 616 to a firstcommunication line 626 within the WC 600. A fourth one of the pins cancouple a second one of the communication lines from the upstream set ofcables 616 to a second communication line 628 within the WC 600. Inimplementations that include a system ground line, a fifth one of thepins can couple the system ground line from the upstream set of cables616 to a system ground line 630 within the WC 600.

The two power distribution lines in the upstream set of cables 616 canbe implemented as two separate cables or configured together as, forexample, a twisted pair cable. The first power line 622 carries a firstsupply voltage V_(sup1) and the second power line 624 is a power supplyreturn. In some implementations, the first supply voltage V_(sup1) is aDC voltage having a value in the range of approximately 5 Volts (V) to42 V, and in one example application, a value of 24 V (although highervoltages may be desirable and are possible in other implementations). Insome other implementations, the first supply voltage V_(sup1) can be apulsed voltage power signal. As described above, the second one of thepower lines 624 can be a power supply return, also referred to as asignal ground (or “common ground”). In other words, the voltage V_(sup2)on the second one of the power lines can be a reference voltage, forexample, a ground. In such implementations, it is the voltage differencebetween the first supply voltage V_(sup1) and the second supply voltageV_(sup2) that is the voltage of interest, as opposed to the actualvalues of the individual voltages V_(sup1) and V_(sup2) relative to thesystem ground. For example, the value of the difference between V_(sup1)and V_(sup2) can be in the range of approximately 5 V to 42 V, and inone example application, 24 V. In implementations that include a systemground line, the system ground line can be implemented as a single cableor configured with the two power distribution lines described above as a3-wire cable.

The two communication lines in the upstream set of cables 616 also canbe implemented as two separate cables or configured together as atwisted pair cable. In some other implementations, the two communicationlines can be bundled with the two power distribution lines justdescribed as a 4-wire cable, or bundled with the two power distributionlines and the system ground line as a 5-wire cable. As described above,pins or other interconnects within the upstream interface 614electrically connect the first and the second communication lines in theupstream set of cables 616 with the first and the second communicationlines 626 and 628, respectively, in the WC 600. The first and the secondcommunication lines 626 and 628, also referred to herein collectively asa communication bus 632, can carry first and second data signals Data₁and Data₂, respectively.

At different times or stages throughout an optical transition cycle orat other times, the data signals Data₁ and Data₂ can be communicatinginformation to the WC 600 from an upstream network controller (such asthe NC 306 or NC 400) or communicating information to the networkcontroller from the WC 600. As an example of a downstream communication,the data signals Data₁ and Data₂ can include a tint command or otherinstructions (for example, such as the secondary tint command describedabove) sent from a network controller to the WC 600. As an example of anupstream communication, the data signals Data₁ and Data₂ can includestatus information (such as a current tint status) or sensor data to besent to the network controller. In some implementations, the signalsData₁ and Data₂ are complementary signals, for example, forming adifferential pair of signals (also referred to herein collectively as adifferential signal).

In some implementations, the communication bus 632 is designed, deployedand otherwise configured in accordance with the Controller Area Network(CAN) vehicle bus standard. In terms of the Open Systems Interconnection(OSI) model, the physical (PHY) layer can be implemented according tothe ISO 11898-2 CAN standard, and the data link layer can be implementedaccording to the ISO 11898-1 CAN standard. In some such implementations,the first data signal Data₁ can refer to the high CAN signal (the “CANHsignal” as it is typically referred to in the CAN protocol), while thesecond data signal Data₂ can refer to the low CAN signal (the “CANLsignal”). In some implementations, the WC 600 communicates with theupstream network controller over the communication bus 632 (and thecoupled communication lines in the upstream set of cables 616) accordingto the CANopen communication protocol. In terms of the OSI model, theCANopen communication protocol implements the network layer and otherlayers above the network layer (for example, the transport layer, thesession layer, the presentation layer and the application layer).According to the CAN protocol, it is the difference between the CANH andCANL signal values that determines the value of the bit beingcommunicated by the differential pair.

In some implementations, the upstream set of cables 616 is directlyconnected with the upstream network controller. In some otherimplementations, the upstream set of cables 616 includes a set ofdroplines connected to (for example, tapped off of) a trunk line thatcontains corresponding power distribution and communication lines. Insome such latter implementations, each of a plurality of WCs 600 can beconnected to the same trunk line via a corresponding set of droplines.In some such implementations, each of the plurality of WCs 600 coupledto the same trunk line can be in communication with the same networkcontroller via the communication lines within the trunk line. In someimplementations, the power distribution lines that power the WCs 600also can be coupled to the same network controller to power the networkcontroller. In some other implementations, a different set of powerdistribution lines can power the network controller. In either case, thepower distribution lines that power the WCs 600 can terminate at a powercontrol panel or other power insertion point.

The WC 600 also includes a second downstream interface (or set ofinterfaces) 618 for coupling to a downstream set of cables 620. Forexample, the downstream set of cables 620 can implement the link 312described above with reference to the network system 300 FIG. 3. In someimplementations, the downstream set of cables 620 also includes at leastfour lines: two power distribution lines and two communication lines.The downstream interface 618 also can include a corresponding number ofpins (not shown)—one pin to couple each of the lines in the downstreamset of cables 620 into the WC 600. For example, a first one of the pinscan couple a first one of the power distribution lines 633 from thedownstream set of cables 620 to a first power drive line 634 within theWC 600. A second one of the pins can couple a second one of the powerdistribution lines 635 from the downstream set of cables 620 to a secondpower drive line 636 within the WC 600. A third one of the pins cancouple a first one of the communication lines 637 from the downstreamset of cables 620 to a first communication line 638 within the WC 600. Afourth one of the pins can couple a second one of the communicationlines 639 from the downstream set of cables 620 to a secondcommunication line 640 within the WC 600. In implementations thatinclude a fifth line, a fifth one of the pins can couple the fifth line641 from the downstream set of cables 620 to a fifth line 642 within theWC 600.

The two power distribution lines 633 and 635 in the downstream set ofcables 620 can be implemented as two separate cables or configuredtogether as, for example, a twisted pair cable. In some implementations,the first power distribution line 633 carries a first applied voltageV_(App1) and the second power distribution line 635 carries a secondapplied voltage V_(App2). In some implementations, the first and thesecond applied voltages V_(App1) and V_(App2) are, for all intents andpurposes, DC voltage signals. In some other implementations, the firstand the second applied voltages V_(App1) and V_(App2) can be pulsedvoltage signals (for example, pulse-width modulated (PWM) signals). Insome implementations, the first applied voltage V_(App1) can have avalue in the range of approximately 0 V to 10 V, and in some specificapplications, in the range of approximately 0 V to 5 V. In someimplementations, the second applied voltage V_(App2) can have a value inthe range of approximately 0 V to −10 V, and in some specificapplications, in the range of approximately 0 V to −5 V. In some otherimplementations, the second power distribution line 635 in thedownstream set of cables 620 can be a power supply return, also referredto as a signal ground or common ground. In other words, the voltageV_(App2) on the second power distribution line can be a referencevoltage, for example, a floating ground.

The first and the second power distribution lines 633 and 635 in thedownstream set of cables 620 are provided to each of the one or moreIGUs 602 controlled by the WC 600. More specifically, the first and thesecond power distribution lines 633 and 635 are electrically connectedto (or coupled with) the busbars and conductive layers that power theelectrochromic states and state transitions of the respective ECDs (suchas, for example, the first and second busbars 126 and 128 and the firstand second TCO layers 114 and 116 in the IGU 100 of FIG. 1). In someimplementations, it is the voltage difference between the first appliedvoltage V_(App1) and the second applied voltage V_(App2) that is thevoltage of interest, as opposed to the actual values of the individualvoltages V_(App1) and V_(App2) relative to a system ground. For example,the value of the difference between V_(App1) and V_(App2)—referred toherein as the “effective applied voltage” V_(Eff) or simply as theapplied voltage V_(Eff) can be in the range of approximately −10 V to 10V in some applications, and in some specific applications in the rangeof approximately −5 V to 5 V, depending on various device parameters anddrive parameters.

The two communication lines 637 and 639 in the downstream set of cables620 also can be implemented as two separate cables or configuredtogether as a twisted pair cable. In some other implementations, the twocommunication lines 637 and 639 can be bundled with the two powerdistribution lines 633 and 635 just described as a 4-wire cable, orbundled with the two power distribution lines and the fifth line as a5-wire cable. As described above, pins or other interconnects within thedownstream interface 618 electrically connect the first and the secondcommunication lines 637 and 639 in the downstream set of cables 620 withthe first and the second communication lines 638 and 640 within the WC600. The first and the second communication lines 638 and 640, alsoreferred to herein collectively as a communication bus 644, can carrydata signals Data₃ and Data₄, respectively.

At different times or stages throughout a transition cycle or at othertimes, the data signals Data₃ and Data₄ can be communicating informationto one or more connected IGUs 602 from the WC 600 or communicatinginformation to the WC 600 from one or more of the IGUs 602. As anexample of a downstream communication, the data signals Data₃ and Data₄can include a status request command or other instructions to be sent toone or more of the IGUs 602. As an example of an upstream communication,the data signals Data₃ and Data₄ can include status information (such asa current tint status) or sensor data sent from one or more of the IGUs602 to the WC 600. In some implementations, the communication bus 644 isdesigned, deployed and otherwise configured in accordance with the1-Wire device communications bus system protocol. In such 1-Wireimplementations, the communication line 638 is a data line and the datasignal Data₃ conveys the data to be communicated, while thecommunication line 640 is a signal ground line and the data signal Data₄provides a reference voltage, such as a signal ground, relative to whichthe data signal Data₃ is measured or compared to recover the data ofinterest.

Example Connection Architecture

In some implementations, the downstream set of cables 620 is directlyconnected with a single IGU 602. In some other implementations, thedownstream set of cables 620 includes a junction that connects thedownstream set of cables 620 to two or more IGUs 602 via correspondingsets of cables. FIG. 7 shows a diagram of an example connectionarchitecture 700 for coupling a window controller to an IGU inaccordance with some implementations. In the illustrated implementation,the connection architecture 700 couples the WC 600 to an IGU 602 thatincludes an ECD 746 (only an end portion of the IGU 602 and ECD 746 areshown). While only one IGU 602 is shown, as described above, theconnection architecture 700 can couple the WC 600 to multiple IGUs 602.To facilitate such multi-IGU implementations, the downstream set ofcables 620 can connect the WC 600 with a junction 748. In someimplementations, the junction 748 electrically couples each of the lines633, 635, 637, 639 and 641 within the downstream set of cables 620 tocorresponding lines 734, 736, 738, 740 and 742 in each of multiplesecondary sets of cables 750 ₁-750 _(N). In this way, a single WC 600can provide power to multiple IGUs 602.

In the illustrated diagrammatic implementation, the IGU 602 includes aplug-in component 752 that facilitates the connection of the downstreamset of cables 620, or more particularly the secondary set of cables 750₁, with the IGU 602 and the ECD 746 within it. In some implementations,the plug-in component 752 is readily insertable and removable from theIGU 602 (for example, for ease of manufacture, maintenance, orreplacement). As shown, the plug-in component 752 includes an interface754 (which can be similar to the interface 618 of the WC 600) forreceiving the power distribution lines 734 and 736, the communicationlines 738 and 740 and the fifth line 742 (in implementations thatinclude a fifth line). In some implementations, the ends of the lines734, 736, 738, 740 and 742 can include connectors that are adapted to beinserted within corresponding connection receivers within the interface754. The plug-in component 752 serves to electrically couple powerdistribution lines 734 and 736 with bus bars 758 and 760, respectively.Bus bars 758 and 760 are, in turn, electrically connected to respectiveconducting layers on either side of the EC stack of the ECD 746.

The plug-in component 752 includes a communication module 756 that isconnected to transmit and receive data to and from the WC 600 over thecommunication lines 738 and 740. In some implementations, thecommunication module 756 can be implemented as a single chip. In somesuch implementations, the communication module 756 can be implemented asa 1-Wire chip that includes a non-volatile memory such as, for example,EEPROM (EPROM), Flash or other suitable solid state memory. Eachcommunication module 756 also can include various processing, controllerand logic functionalities, authentication capabilities, or otherfunctionalities or capabilities. When implemented as a 1-Wire chip, eachcommunication module 756 can be identified with a unique 1-Wire ID (forexample, a 48-bit serial number). One example of such a 1-Wire chipsuitable for use in some implementations is the DS28EC20, 20 Kb 1-wireEPROM chip provided by Maxim Integrated Products, Inc. of San Jose,Calif. In some other implementations, the communication module 756 caninclude a memory chip (including non-volatile memory and memorycontroller functionality) and a separate ID chip storing the unique ID(for example, the 1-Wire ID). Some examples of functions and hardwarethat can be associated with such a 1-Wire chip are described in U.S.patent application Ser. No. 13/049,756 (Attorney Docket No. VIEWP007)filed Mar. 16, 2011 and titled MULTIPURPOSE CONTROLLER FOR MULTISTATEWINDOWS, which is hereby incorporated by reference in its entirety andfor all purposes.

In some implementations, various device or drive parameters for theparticular ECD 746 are programmed into and stored within the memorycomponent within the communication module 756 (for example, during or atthe end of manufacturing or fabrication of the ECD or IGU or at a latertime during or after installation). For example, such pre-programmeddevice parameters for the ECD 746 can include a length, width,thickness, cross-sectional area, shape, age, model number, versionnumber, or number of previous optical transitions of or associated withthe respective ECD 746 (or of a pane on which the ECD is formed orotherwise arranged). Pre-programmed drive parameters can include, forexample, a ramp-to-drive rate, a drive voltage, a drive voltageduration, a ramp-to-hold rate and a holding voltage for each possiblecombination of current tint state and target tint state. In someimplementations, the processing unit 604 reads the device parameters anddrive parameters prior to the start of each tint state transition.Additionally or alternatively, in some implementations, the processingunit 604 reads the device and drive parameters when the respective IGU602 is powered on and commissioned. The processing unit 604 canadditionally or alternatively read the device and drive parametersperiodically, such as daily.

In some other implementations, a surface of the communication module 756can additionally or alternatively have an identifier (ID) scribed oretched on it. For example, the ID can be scribed or etched on thecommunication module 756 during or after production of the ECD. In someimplementations, the ID is a lite ID of the lite (pane) on which the ECDis formed. Additionally or alternatively, the ID can include an IGU IDof the associated IGU 302. In some implementations, the WC 304 will thenread this information optically or electronically after it is connectedto the ECD. In some such implementations, the WC 304 can retrieveparameters such as the length, width, thickness, cross-sectional area,shape, age, model number, version number etc. from the MC 308. Forexample, the MC 400 can previously be programmed to store suchparameters. In some other implementations, the MC 400 can retrieve suchparameters from the producer of the ECD/IGU through an externalcommunication interface (for example, the interface 410) either inadvance or in response to a request for such parameters or relatedinformation by the WC 304 or NC 306.

The number and size of the IGUs 602 that each WC 600 can drive isgenerally limited by the load on the WC 600. The load is typicallydefined by the voltage, current, or power requirements necessary tocause the desired optical transitions in the IGUs 602 driven by the WC600 within a desired timeframe. Because the maximum load that a given WC600 can drive is generally limited by the capabilities and safeoperating ranges of the electrical components within the WC 600, or bythe power carrying limitations of the power drive lines 634 and 636 orthe power distribution lines 633 and 635, there can be a tradeoffbetween acceptable transition time and the number and size of the ECDsdriven by each WC 600.

The power requirements necessary to cause the desired opticaltransitions in the IGUs 602 driven by a given WC 600 within a desiredtimeframe are, in turn, a function of the surface area of the connectedIGUs 602, and more particularly, the surface area of the ECDs within theIGUs 602. This relationship can be nonlinear; that is, the powerrequirements can increase nonlinearly with the surface area of the ECDs.The nonlinear relationship can exist, at least in part, because thesheet resistances of the conductive layers (such as the first and secondTCO layers 114 and 116 of the IGU 100) used to deliver the appliedvoltages to the electrochromic stack of the ECD increase nonlinearlywith distance across the length and width of the respective conductivelayers. For example, it can take more power to drive a single 50 ft² ECDthan to drive two 25 ft² ECDs. System- or building-wide powerconsiderations also may require that the power available to each WC 600be limited to less than that which the WC 600 is capable of handling andproviding to the connected IGUs 602.

In some implementations, such as that described with reference to theconnection architecture 700 of FIG. 7, each of the IGUs 602 connectedwith the WC 600 can include its own respective plug-in component 752 andcommunication module 756. Each communication module 756 can include arespective 1-Wire chip storing device parameters for the respective ECD.In some implementations, each of the parallel-connected IGUs 602receives the same voltages V_(App1) and V_(App2). In some suchimplementations, it can generally be desirable or preferable for each ofthe IGUs 602 connected with a single WC 600 to have the same or similardevice parameters (such as surface area) so that each of the respectiveECDs behaves the same or similarly responsive to the voltages V_(App1)and V_(App2). For example, it is generally desirable that each of theIGUs 602 connected with a given WC 600 have the same tint whether duringa transition or during a holding period between transitions. However, inimplementations in which the IGUs 602 have different device parameters,the processing unit 604 can compare or otherwise integrate the deviceparameters from each of the connected IGUs 602 to generate a commandsignal V_(Drive) that results in a best or least harmful effectiveapplied voltage V_(Eff), for example, a voltage that is maintainedwithin a safe but effective range for all of the connected IGUs 602.

In some other implementations, there can be a one-to-one relationshipbetween the number of WCs 600 and IGUs 602; that is, each IGU 602 can bedriven and otherwise controlled by a respective dedicated WC 600. Insome such integrated implementations, the WC 600 can be located withinthe IGU 602, for example, within a housing having a thin form factorwithin the interior volume of the IGU. In some other implementations,the WC 600 can be located adjacent the IGU 602, for example, hidden by aframe or mullion that supports the IGU 602. In some otherimplementations, the WC 600 can be located at an interior lower boundaryor at an interior corner of the IGU 602 where it is less visible ornoticeable but still accessible to an installer or technician. Forexample, such latter implementations can be useful for applications inwhich easier access to the WC 600 is desirable (for example, to replace,repair or map the WC 600).

Additionally, such implementations also can be desirable where the WC600 can include an energy storage device (for example, a rechargeablebattery, battery pack or supercapacitor), that is also readilyreplaceable by a technician. For example, the IGU can include a dockingmodule that the battery can plug into. In such case, the docking modulecan be electrically connected to the WC 600 rather than the batterydirectly. In implementations in which the WC 600 is integrated with theIGU 602, the WC 600 itself can include a docking module that the batterycan plug into. In implementations in which the WC 600 is integrated withthe IGU 602, the IGU 602 can still include a plug-in component 752 thatconnects with the WC 600. In some other integrated implementations, theWC 600 can be directly connected to the busbars of the associated ECD.In such latter integrated implementations, the communication modulestoring the device parameters of the ECD can be located within the WC600, for example, in a non-volatile memory within the WC 600. Moreexamples of the use of integrated window controllers and energy storagedevices are described in U.S. patent application Ser. No. 14/951,410(Attorney Docket No. VIEWP008X1US) filed Nov. 24, 2015 and titledSELF-CONTAINED EC IGU, and PCT Patent Application No. PCT/US16/41176(Attorney Docket No. VIEWP080WO) filed Jul. 6, 2016 and titled POWERMANAGEMENT FOR ELECTROCHROMIC WINDOW NETWORKS, both of which are herebyincorporated by reference in their entireties and for all purposes.

Processing Unit 604

At a high level, the processing unit 604 functions to communicate withthe upstream network controller and to control the tint states of theIGUs 602 connected with the WC 600. One primary function of theprocessing unit 604 is to generate a command signal V_(DCmnd). As willbe described in more detail below, the command signal V_(DCmnd) isprovided to the drive circuit 608 for generating the applied voltagesignals V_(App1) and V_(App2), which are output from the WC 600 fordriving one or more IGUs 602 controlled by the WC 600. In variousimplementations the processing unit 604 can generate the command signalV_(DCmnd) based on a number of different device parameters, driveparameters, input values, algorithms or instructions. For example, theprocessing unit 604 can generate the command signal V_(DCmnd) based on atint command received from the upstream network controller. As describedabove, the tint command can include a tint value corresponding to atarget tint state for the IGUs 602 controlled by the WC 600.

In some implementations, responsive to receiving a tint command, theprocessing unit 604 initiates a tinting transition in one or more of theIGUs 602 controlled by the WC 600. In some implementations, theprocessing unit 604 calculates, selects, determines or otherwisegenerates the command signal V_(DCmnd) based on drive parametersincluding the current tint state of an IGU 602 to be transitioned andthe target tint state of the IGU 602 (based on the tint value in thetint command). The processing unit 604 also can generate the commandsignal V_(DCmnd) based on other drive parameters, for example, aramp-to-drive rate, a drive voltage, a drive voltage duration, aramp-to-hold rate and a holding voltage for each possible combination ofcurrent tint state and target tint state. Other drive parameters caninclude parameters based on current or recent sensor data, for example,an indoor temperature, an outdoor temperature, a temperature within theinterior volume of the IGU 602 (or of one or more of the panes), a lightintensity in a room adjacent the IGU 602 and a light intensity outsideof the IGU 602, among other suitable or desirable parameters. In someimplementations, such sensor data can be provided to the WC 600 via theupstream network controller over communication lines 626 and 628.Additionally or alternatively, the sensor data can be received fromsensors located within or on various portions of the IGU 602. In somesuch implementations, the sensors can be within or otherwise coupledwith a communication module within the IGU 602 (such as thecommunication module 756). For example, multiple sensors includingphotosensors, temperature sensors or transmissivity sensors can becoupled via the same communication lines 739 and 741 shown in FIG. 7according to the 1-Wire communication protocol.

In some implementations, the processing unit 604 also can generate thecommand signal V_(DCmnd) based on the device parameters associated withthe ECD within the IGU 602. As described above, the device parametersfor the ECD can include a length, width, thickness, cross-sectionalarea, shape, age, model number, version number, or number of previousoptical transitions of or associated with the respective ECD (or of apane on which the ECD is formed or otherwise arranged). In someimplementations, the processing unit 604 is configured to track thenumber of tinting transitions for each of the connected IGUs 602.

In some implementations, the processing unit 604 generates the commandsignal V_(DCmnd) based on a voltage control profile, for example, suchas that described above with reference to FIG. 2. For example, theprocessing unit 604 can use the drive parameters and device parametersto select a voltage control profile from a predefined set of voltagecontrol profiles stored in a memory within or accessible by theprocessing unit 604. In some implementations, each set of voltagecontrol profiles is defined for a particular set of device parameters.In some implementations, each voltage control profile in a given set ofvoltage control profiles is defined for a particular combination ofdrive parameters. The processing unit 604 generates the command signalV_(DCmnd) such that the drive circuit 608 implements the selectedvoltage control profile. For example, the processing unit 604 adjuststhe command signal V_(DCmnd) to cause the drive circuit 608 to, in turn,adjust the applied voltage signals V_(App1) and V_(App2). Morespecifically, the drive circuit 608 adjusts the applied voltage signalsV_(App1) and V_(App2) such that the effective voltage V_(Eff) appliedacross the ECD tracks the voltage levels indicated by the voltagecontrol profile throughout the progression through the profile.

In some implementations, the processing unit 604 also can modify thecommand signal V_(DCmnd) dynamically (whether during a transition orduring a holding period after a transition) based on sensor data. Asdescribed above, such sensor data can be received from various sensorswithin or otherwise integrated with the connected IGUs 602 or from otherexternal sensors. In some such implementations, the processing unit 604can include intelligence (for example, in the form of programminginstructions including rules or algorithms), that enable the processingunit 604 to determine how to modify the command signal V_(DCmnd) basedon the sensor data. In some other implementations, the sensor datareceived by the WC 600 from such sensors can be communicated to thenetwork controller, and in some instances from the network controller tothe master controller. In such implementations, the network controlleror the master controller can revise the tint value for the IGUs 602based on the sensor data and transmit a revised tint command to the WC600. Additionally or alternatively, the network controller or the mastercontroller can receive sensor data from one or more other sensorsexternal to the building, for example, one or more light sensorspositioned on a roof top or a facade of the building. In some suchimplementations, the master controller or the network controller cangenerate or revise the tint value based on such sensor data.

In some implementations, the processing unit 604 also can generate ormodify the drive signal V_(Drive) dynamically based on one or morefeedback signals V_(Feed) received from the feedback circuit 610. Forexample, and as will be described in more detail below, the feedbackcircuit 610 can provide one or more voltage feedback signals V_(OC)based on actual voltage levels detected across the ECDs (for example, asmeasured during periodic open circuit instances), one or more currentfeedback signals V_(Cur) based on actual current levels detected throughthe ECDs, or based on one or more voltage compensation signals V_(Comp)associated with voltage drops detected or determined along the powertransmission lines that provide the applied voltage signals V_(App1) andV_(App2) to the IGUs 602.

Generally, the processing unit 604 can be implemented with any suitableprocessor or logic device, including combinations of such devices,capable of performing the functions or processes described herein. Insome implementations, the processing unit 604 is a microcontroller (alsoreferred to as a microcontroller unit (MCU)). In some more specificapplications, the processing unit 604 can be a microcontrollerparticularly designed for embedded applications. In someimplementations, the processing unit 604 includes a processor core (forexample, a 200 MHz processor core or other suitable processor core) aswell as a program memory (for example, a 2018 KB or other suitablenon-volatile memory), a random-access memory (RAM) (for example, a 512KB or other suitable RAM), and various I/O interfaces. The programmemory can include, for example, code executable by the processor coreto implement the functions, operations or processes of the processingunit 604.

In some implementations, the RAM can store status information for theIGUs 602 controlled by the WC 600. The RAM also can store the deviceparameters for the ECDs within the IGUs 602. In some otherimplementations, the processing unit 604 can store such statusinformation or device parameters in another memory device (for example,a Flash memory device) external to the processing unit 604 but alsowithin the WC 600. In some specific implementations, the I/O interfacesof the processing unit 604 include one or more CAN interfaces, one ormore synchronous serial interfaces (for example, 4-wire SerialPeripheral Interface (SPI) interfaces), and one or more Inter-IntegratedCircuit (I²C) interfaces. One example of such a controller suitable foruse in some implementations is the PIC32MZ2048ECH064 controller providedby Microchip Technology Inc. of Chandler, Ariz.

In the implementation illustrated in FIG. 6, the WC 600 additionallyincludes a data bus transceiver 664. The data bus transceiver 664 iscoupled with the upstream interface 614 via the communication bus 632.The data bus transceiver 664 also is coupled with the processing unit604 via a communication bus 666. As described above, in someimplementations, the communication bus 632 is designed, deployed andotherwise configured in accordance with the CAN bus standard, which is adifferential bus standard. In some implementations, the communicationbus 666 also conforms to the CAN bus standard and includes adifferential pair of lines for transferring a differential pair ofsignals. As such, the data bus transceiver 664 can include two sets ofdifferential ports; a first set for coupling with the communication bus632 and a second set for coupling with the communication bus 666, whichin turn is coupled with a CAN interface of the processing unit 604.

In various implementations, the data bus transceiver 664 is configuredto receive data from a network controller (such as the NC 500) via thecommunication bus 632, process the data, and transmit the processed datato the processing unit 604 via the communication bus 666. Similarly, thedata bus transceiver 664 is configured to receive data from theprocessing unit 604 via the communication bus 666, process the data, andtransmit the processed data over the communication bus 632 to theinterface 614 and ultimately over the upstream set of cables 616 to thenetwork controller. In some such implementations, processing the dataincludes converting or translating the data from a first protocol to asecond protocol (for example, from a CAN protocol (such as CANopen) to aprotocol readable by the processing unit 604 and vice versa). Oneexample of such a data bus transceiver suitable for use in someimplementations is the SN65HVD1050 data bus transceiver provided byTexas Instruments Inc. of Dallas, Tex. In some other implementations,the processing unit 604 can include an integrated data bus transceiveror otherwise include functionalities of the data bus transceiver 664rendering the inclusion of the external data bus transceiver 664unnecessary.

Power Circuit

At a high level, the power circuit 606 is operable to receive power fromthe power supply lines 622 and 624 and to provide power to variouscomponents of the WC 600 including the processing unit 604, the drivecircuit 608, the feedback circuit 610 and the communications circuit612. As described above, the first power supply line 622 receives asupply voltage V_(Sup1), for example, a DC voltage having a value in therange of approximately 5 V to 42 V (relative to the supply voltageV_(Sup2)), and in one example application, a value of 24 V (althoughhigher voltages may be desirable and are possible in otherimplementations). As is also described above, the second power supplyline 624 can be a power supply return. For example, the voltage V_(Sup2)on the second power supply line 624 can be a reference voltage, forexample, a floating ground.

The power circuit 606 includes at least one down converter (alsoreferred to herein as a “buck converter”) for stepping down the supplyvoltage V_(Sup1). In the illustrated implementation, the power circuit606 includes two down converters: a first relatively low power (LP) downconverter 668 and a second relatively high power (HP) down converter670. The LP down converter 668 functions to step down the supply voltageV_(Sup1) to a first down-converted voltage V_(Dwn1). In someimplementations, the down-converted voltage V_(Dwn1) can have a value inthe range of approximately 0 to 5 V, and in one example application, avalue of approximately 3.3 V. The down-converted voltage V_(Dwn1) isprovided to the processing unit 604 for powering the processing unit604. One example of an LP down converter suitable for use in someimplementations is the TPS54240 2.5 Ampere (Amp) DC-DC step-downconverter provided by Texas Instruments Inc. of Dallas, Tex.

The HP down converter 670 functions to step down the supply voltageV_(Sup1) to a second down-converted voltage V_(Dwn2). One example of anHP down converter suitable for use in some implementations is theTPS54561 5 Amp DC-DC step-down converter provided by Texas InstrumentsInc. of Dallas, Tex. In some implementations, the down-converted voltageV_(Dwn2) can have a value in the range of approximately 6V to 24V, andin one example application, a value of approximately 6 V. Thedown-converted voltage V_(Dwn2) is provided to the voltage regulator680, described below with reference to the drive circuit 608. In someimplementations, the down-converted voltage V_(Dwn2) also is provided tothe rest of the components within the WC 600 that require power toperform their respective functions (although these connections are notshown in order to avoid over complicating the illustration and to avoidobscuring the other components and connections).

In some implementations, the HP down converter 670 provides thedown-converted voltage V_(Dwn2) only when enabled (or instructed) to doso, for example, when or while the processing unit 604 asserts an enablesignal En. In some implementations, the enable signal En is provided tothe HP down converter 670 via a Serial Peripheral Interface (SPI)interface bus 686. Although the SPI interface bus 686 may be describedherein in the singular form, the SPI bus 686 may collectively refer totwo or more SPI buses, each of which can be used to communicate with arespective component of the WC 600. In some implementations, theprocessing unit asserts the enable signal En only when the WC 600 is inan “active mode,” as opposed to a “sleep mode.”

In some implementations, the power circuit 606 further includes or iscoupled with an energy storage device (or “energy well”) 672 such as,for example, a capacitive storage device such as a rechargeable battery(or set of batteries) or a supercapacitor. For example, one example of asupercapacitor suitable for use in some implementations can have acapacitance C_(S) of at least 400 Farads at 0.4 watt hours (Wh). In someimplementations, the energy storage device 672 can be charged by acharger 674. In some such implementations, the charger 674 can bepowered by the supply voltage V_(Sup1). One example of such a chargersuitable for use in some implementations is the LT3741 constant-current,constant-voltage, step-down controller provided by Linear TechnologyCorp. of Milpitas, Calif. In some implementations, the charger 674 alsois configured to provide power stored in the energy storage device 672to the power supply line 622.

In some implementations, the charger 674 can alternatively oradditionally be powered by one or more photovoltaic (or “solar”) cells.For example, such photovoltaic (PV) cells can be integrated onto or intothe IGUs 602, such as on one or more panes of the IGUs, controlled bythe WC 600. In some such implementations, the power received via the PVcell can be regulated by a voltage regulator 676 prior to being providedto the charger 674 and ultimately the energy storage device 672. Forexample, the voltage regulator 676 can serve to step up or step down thevoltage of the power received from the PV cells. The voltage regulator676 also can generally be used to regulate the power provided by the PVcells as such power fluctuates throughout a day, for example, tomaintain the voltage of the power at a fixed level. In someimplementations, when the power stored in the energy storage device 672is desired or needed, it gets released via the charger 674. In someimplementations, to prevent back drive (that is, to ensure that powerfrom the energy storage device 672 or the PV cells does not flowupstream over the upstream set of cables 616), the power circuit 606 canadditionally include an asymmetric conductor 678, for example, a lowloss semiconductor diode such as a Schottky junction diode or a p-njunction diode. The use of such a diode 678 can be especiallyadvantageous in implementations in which one or more of the supplyvoltages V_(Sup1) and V_(Sup2) are pulsed. More examples of the use ofintegrated PV cells are described in U.S. patent application Ser. No.14/951,410 (Attorney Docket No. VIEWP008X1) filed Nov. 24, 2015 andtitled SELF-CONTAINED EC IGU, which is hereby incorporated by referencein its entirety and for all purposes.

The integration of energy storage devices can be advantageous for anumber of reasons, whether such devices are included within respectiveWCs 600 (like the energy storage device 672) or are otherwisedistributed throughout a network system (such as the network system300). For example, the power circuit 606 within each WC 600 cansupplement or augment the power provided by the respective power supplylines 622 and 624 with power drawn from the energy storage device 672.Additionally or alternatively, energy storage devices external to theWCs 600 can provide power directly to the power distribution lines thatdistribute power throughout the network system to supply the WCs 600.Such implementations can be especially advantageous in high demandinstances in which many IGUs 602 are to be transitioned concurrently. Intimes of lower demand, the normal power supply (for example, the powersupply provided by a building source) can recharge the energy storagedevices. More examples of the use of energy storage devices aredescribed in U.S. patent application Ser. No. 14/951,410 (AttorneyDocket No. VIEWP008X1) filed Nov. 24, 2015 and titled SELF-CONTAINED ECIGU, and PCT Patent Application No. PCT/US16/41176 (Attorney Docket No.VIEWP080WO) filed Jul. 6, 2016 and titled POWER MANAGEMENT FORELECTROCHROMIC WINDOW NETWORKS, both of which are hereby incorporated byreference in their entireties and for all purposes.

Additionally or alternatively, in some implementations, the transitionsof the IGUs 602 can be staggered. For example, the MC 400 or the NC 500can issue tint commands for subsets of the WCs 600 at different times soas to keep the total power consumed by the network system (or a portionof the network system) at any given time under a desirable, safe,permitted or maximum limit. In some other implementations, the WCs 304can be programmed via various parameters received from the MC 400 or NC500 to delay their transitions. For example, the secondary tint commandissued by the NC 500 also can include a delay value that informs the WC400 to begin a tint change after the time associated with the delayvalue has lapsed. As another example, the secondary tint command issuedby the NC 500 also can include a time value that informs the WC 400 tobegin a tint change when a time associated with the time value has beenreached. In these latter two examples, the NC 500 can issue tintcommands to the WCs 304 approximately simultaneously orcontemporaneously while ensuring that staggering of the transitions isstill achieved.

Drive Circuit

At a high level, the drive circuit 608 is generally operable to receivethe command signal V_(DCmnd) from the processing unit 604 and to providethe applied voltage signals V_(App1) and V_(App2) for driving theconnected IGUs 602 based on the command signal V_(DCmnd). The drivecircuit 608 includes a voltage regulator 680 that receives thedown-converted voltage V_(Dwn2) from the HP down converter 670 in thepower circuit 606. The voltage regulator 680 regulates, adjusts orotherwise transforms the voltage V_(Dwn2) to provide (or “generate”)first and second regulated voltage signals V_(P1) and V_(P2) based onthe command signal V_(DCmnd). In some implementations, the voltageregulator 680 is a buck-boost converter; that is, the voltage regulator680 can be capable of functioning as a down converter to step down thevoltage V_(Dwn2) as well as an up converter to step up the input voltageV_(Dwn2). Whether the voltage regulator 680 behaves as a down converteror as an up converter is dependent on the command signal V_(DCmnd), asis the magnitude of the down conversion or up conversion, respectively.In some more specific implementations, the voltage regulator 680 is asynchronous buck-boost DC-DC converter. In some such implementations,the regulated voltage signals V_(P1) and V_(P2) are effectivelyfixed-amplitude DC signals from the perspective of the IGUs 602, and inparticular, the ECDs within the IGUs 602.

As described in more detail above, the processing unit 604 can generatethe command signal V_(DCmnd) based on a number of different parameters,input values, algorithms or instructions. In some implementations, theprocessing unit 604 generates the command signal V_(DCmnd) in the formof a digital voltage signal. In some such implementations, the drivecircuit 608 can additionally include a digital-to-analog converter (DAC)682 for converting the digital command signal V_(DCmnd) to an analogcommand voltage signal V_(ACmnd). In some implementations, the DAC 682can be external to the processing unit 604, while in some otherimplementations, the DAC 682 is internal to the processing unit 604. Insuch implementations, the voltage regulator 680 more specificallygenerates the regulated voltage signals V_(P1) and V_(P2) based on thecommand voltage signal V_(CCmnd). One example of a DAC suitable for usein some implementations is the AD5683R DAC by Analog Devices Inc. ofNorwood, Mass.

In some specific implementations, the regulated voltage signals V_(P1)and V_(P2) are rectangular wave (or “pulsed”) DC signals, for example,pulse-width modulated (PWM) voltage signals. In some suchimplementations, the voltage regulator 680 includes an H-bridge circuitto generate the regulated voltage signals V_(P1) and V_(P2). In somesuch implementations, each of the regulated voltage signals V_(P1) andV_(P2) has the same frequency. In other words, the period from the startof a current pulse to the start of the next pulse in each of theregulated voltage signals V_(P1) and V_(P2) has the same time duration.In some implementations, the voltage regulator 680 is operable to modifythe duty cycles of the respective voltage signals V_(P1) and V_(P2) suchthat the respective duty cycles are not equal. In this way, while theamplitude (or “magnitude”) of the pulses (or “on” durations) of thefirst regulated voltage signal V_(P1) can be equal to the magnitude ofthe pulses of the second regulated voltage signal V_(P2), each of thefirst and the second regulated voltage signals V_(P1) and V_(P2) canhave a different effective DC voltage magnitude from the perspective ofthe corresponding busbars and conducting layers of the ECDs in the IGUs602. However, in some other implementations, the voltage regulator 680can additionally or alternatively modify the respective magnitudes ofthe pulses of the voltage signals V_(P1) and V_(P2).

For example, consider an application in which each of the pulses of eachof the regulated voltage signals V_(P1) and V_(P2) has an amplitude of 5V, but in which the first voltage signal V_(P1) has a 60% duty cyclewhile the second voltage signal V_(P2) has a 40% duty cycle. In such anapplication, the effective DC voltage provided by each of the regulatedvoltage signals V_(P1) and V_(P2) can be approximated as the product ofthe respective pulse amplitude and the fraction of the duty cycleoccupied the respective pulses. For example, the effective DC voltageprovided by the first voltage signal V_(P1) can be approximated as 3 V(the product of 5 V and 0.6) while the effective voltage provided by thesecond voltage signal V_(P2) can be approximated as 2 V (the product of5 V and 0.4). In some implementations, the duty cycle of first voltagesignal V_(P1) is complementary to the duty cycle of the second voltagesignal V_(P2). For example, as in the case of the example just provided,if the first voltage signal V_(P1) has a duty cycle of X %, the dutycycle of the second voltage signal V_(P2) can be Y %, where Y %=100%-X%. In some such implementations, the “on” durations of the first voltagesignal V_(P1) can coincide with the “off” durations of the secondvoltage signal V_(P2), and similarly, the “off” durations of the firstvoltage signal V_(P1) can coincide with the “on” durations of the secondvoltage signal V_(P2). In some other implementations, the duty cycles donot necessarily have to be complementary; for example, the first voltagesignal V_(P1) can have a duty cycle of 50% while the second voltagesignal V_(P2) can have a duty cycle of 15%.

As described above, in some implementations, the regulated voltagesignals V_(P1) and V_(P2) are effectively fixed-amplitude DC signalsfrom the perspective of the IGUs 602, and in particular, the ECDs withinthe IGUs 602. To further such implementations, the voltage regulator 680also can include one or more electronic filters, and in particular, oneor more passive filter components such as one or more inductors. Suchfilters or filter components can smooth out the regulated voltagesignals V_(P1) and V_(P2) prior to their provision to ensure that theregulated voltage signals V_(P1) and V_(P2) are effectivelyfixed-amplitude DC signals. To further facilitate the smoothing of theregulated voltage signals V_(P1) and V_(P2), the frequency of the pulsesin the voltage signals V_(P1) and V_(P2) can be greater than or equal to1 kilohertz (kHz) in some implementations. For example, as one ofordinary skill in the art will appreciate, the greater the frequency ofthe voltage oscillations applied to a conductor, the less able theelectric charge in the conductor is able to react to the voltageoscillations. Additionally, the greater the inductance of an inductor,the more smoothing out of the voltage oscillations that are providedthrough the inductor.

In some implementations, the voltage regulator 680 can advantageously becapable of operating in a burst mode to reduce the power consumption ofthe WC 600 over time. In the burst mode of operation, the voltageregulator 680 automatically enters and exits the burst mode to minimizethe power consumption of the voltage regulator 680. One example of sucha voltage regulator suitable for use in some implementations is theLTC3112 15 V, 2.5 Amp Synchronous Buck-Boost DC/DC Converter provided byLinear Technology Corp. of Milpitas, Calif.

In some implementations, the regulated voltage signals V_(P1) and V_(P2)are the applied voltage signals V_(App1) and V_(App2), respectively. Insome such implementations, the difference between the regulated voltagesignals V_(P1) and V_(P2) is the effective voltage V_(Eff). In someimplementations, to effect a lightening tinting transition, theprocessing unit 604 generates the command signal V_(DCmnd) such that thevoltage regulator 680 provides a positive effective voltage V_(Eff),while to effect a darkening tinting transition, the processing unit 604generates the command signal V_(DCmnd) such that the voltage regulator680 provides a negative effective voltage V_(Eff). Conversely, in someother implementations involving different electrochromic layers orcounter electrode layers, a darkening tinting transition is achieved byproviding a positive effective voltage V_(Eff) while a lighteningtinting transition is achieved by providing a negative effective voltageV_(Eff).

Either way, the voltage regulator 680 can provide a positive effectivevoltage V_(Eff) by increasing the duty cycle of the first voltage signalV_(P1) or by decreasing the duty cycle of the second voltage signalV_(P2) such that the duty cycle of the first voltage signal V_(P1) isgreater than the duty cycle of the second voltage signal V_(P2), andconsequently, the effective DC voltage of the first applied voltagesignal V_(App1) is greater than the effective DC voltage of the secondapplied voltage signal V_(App2). Similarly, the voltage regulator 680can provide a negative effective voltage V_(Eff) by decreasing the dutycycle of the first voltage signal V_(P1) or by increasing the duty cycleof the second voltage signal V_(P2) such that the duty cycle of thefirst voltage signal V_(P1) is less than the duty cycle of the secondvoltage signal V_(P2), and consequently, the effective DC voltage of thefirst applied voltage signal V_(App1) is less than the effective DCvoltage of the second applied voltage signal V_(App2).

In some other implementations, including that illustrated in FIG. 6, thedrive circuit 608 additionally includes a polarity switch 682. Thepolarity switch 682 receives the two regulated voltage signals V_(P1)and V_(P2) from the voltage regulator 680 and outputs the appliedvoltage signals V_(App1) and V_(App2) that are provided to the powerlines 634 and 636, respectively. The polarity switch 482 can be used toswitch the polarity of the effective voltage V_(Eff) from positive tonegative, and vice versa. Again, in some implementations, the voltageregulator 680 can increase the magnitude of V_(P1) relative to V_(P2),and thus increase the magnitude of V_(Eff), by increasing the duty cycleof the first voltage signal V_(P1) or by decreasing the duty cycle ofthe second voltage signal V_(P2). Similarly, the voltage regulator 680can decrease the magnitude of V_(P1) relative to V_(P2), and thusdecrease the magnitude of V_(Eff), by decreasing the duty cycle of thefirst voltage signal V_(P1) or by increasing the duty cycle of thesecond voltage signal V_(P2).

In some other implementations, the second voltage V_(P2) can be a signalground. In such implementations, the second voltage V_(P2) can remainfixed or floating during transitions as well as during times betweentransitions. In such implementations, the voltage regulator 680 canincrease or decrease the magnitude of V_(P1), and thus the magnitude ofV_(Eff), by increasing or decreasing the duty cycle of the first voltagesignal V_(P1). In some other such implementations, the voltage regulator680 can increase or decrease the magnitude of V_(P1), and thus themagnitude of V_(Eff), by directly increasing or decreasing the amplitudeof the first voltage signal V_(P1) with or without also adjusting theduty cycle of the first voltage signal V_(P1). Indeed, in such latterimplementations, the first voltage signal V_(P1) can be an actual fixedDC signal rather than a pulsed signal.

In implementations that include a polarity switch 682, the secondvoltage signal V_(P2) can be a signal ground and the first voltagesignal V_(P1) can always be a positive voltage relative to the secondvoltage signal V_(P2). In such implementations, the polarity switch 682can include two configurations (for example, two electricalconfigurations or two mechanical configurations). The processing unit604 can control which of the configurations the polarity switch 682 isin via a control signal V_(Polar) provided, for example, over the SPIbus 686. For example, the processing unit 604 can select the firstconfiguration when implementing a lightening transition and the secondconfiguration when implementing a darkening transition. For example,while the polarity switch 682 is in the first configuration, thepolarity switch can output a positive first applied voltage signalV_(App1) relative to the second applied voltage signal V_(App2).Conversely, while the polarity switch 682 is in the secondconfiguration, the polarity switch can output a negative first appliedvoltage signal V_(App1) relative to the second applied voltage signalV_(App2).

In some implementations, while in the first configuration, the polarityswitch 682 passes the first voltage signal V_(P1) (or a buffered versionthereof) as the first applied voltage signal V_(App1) and passes thesecond voltage signal V_(P2) (or a grounded version thereof) as thesecond applied voltage signal V_(App2), resulting in a positiveeffective voltage V_(Eff). In some implementations, while in the secondconfiguration, the polarity switch 682 passes the first voltage signalV_(P1) (or a buffered version thereof) as the second applied voltagesignal V_(App2) and passes the second voltage signal V_(P2) (or agrounded version thereof) as the first applied voltage signal V_(App2),resulting in a negative effective voltage V_(Eff). In someimplementations, the polarity switch 682 can include an H-bridgecircuit. Depending on the value of V_(Polar), the H-bridge circuit canfunction in the first configuration or the second configuration. Oneexample of a polarity switch suitable for use in some implementations isthe IRF7301 HEXFET Power MOSFET provided by International RectifierCorp. of San Jose, Calif.

In some implementations, when switching from a positive voltage V_(Eff)to a negative voltage V_(Eff), or vice versa, the polarity switch 682can be configured to switch from a first conducting mode, to a highimpedance mode and then to a second conducting mode, or vice versa. Fordidactic purposes, consider an example in which the first regulatedvoltage V_(P1) is at a positive hold value and in which the polarityswitch 682 is in the first configuration. As described above, in someimplementations the polarity switch 682 passes V_(P1) (or a bufferedversion thereof) as the first applied voltage V_(App1) resulting in afirst applied voltage V_(App1) that also is at the positive hold value.To simplify the illustration, also assume that V_(P2) and V_(App2) areboth signal grounds. The result would be an effective applied voltageV_(Eff) at the positive hold value. Now consider that the processingunit 604 is initiating a tinting transition that will result in an endstate in which the effective applied voltage V_(Eff) is at a negativehold value. In some implementations, to effect the tinting transition,the processing unit 604 adjusts the command signal V_(DCmnd) to causethe voltage regulator 680 to lower the magnitude of the voltage V_(P1)based on a negative ramp-to-drive profile. In some implementations, asthe magnitude of the voltage V_(P1) reaches a threshold value close tozero (for example, 10 millivolts (mV)), the processing unit 604 changesthe polarity switching signal V_(Polar) from a first value to a secondvalue to cause the polarity switch 682 to switch from a positiveconducting mode (the first configuration described above) to a highimpedance mode.

While in the high impedance mode the polarity switch 682 does not passV_(P1). Instead, the polarity switch 682 can output values of V_(App1)(or V_(App2)) based on predefined calculations or estimations.Meanwhile, the voltage regulator 680 continues to decrease the magnitudeof V_(P1) to zero. When the magnitude of V_(P1) reaches zero, thevoltage regulator 680 begins increasing the magnitude of V_(P1) up tothe magnitude of the negative drive value. When the magnitude of V_(P1)reaches a threshold value (for example, 10 mV), the processing unit 604then changes the polarity switching signal V_(Polar) from the secondvalue to a third value to cause the polarity switch 682 to switch fromthe high impedance mode to a negative conducting mode (the secondconfiguration described above). As described above, in some suchimplementations, the polarity switch 682 passes V_(P1) as the secondapplied voltage V_(App2), while the first applied voltage V_(App1) is asignal ground. To summarize, while the magnitude of V_(P1) is greaterthan or equal to a threshold voltage (for example, 10 mV) the polarityswitch 682 passes the regulated voltage V_(P1) as either the firstapplied voltage V_(App1) or the second applied voltage V_(App2),depending on whether the polarity switch 682 is in the positiveconducting mode (first configuration) or the negative conducting mode(second configuration), respectively. As such, the effective appliedvoltage V_(Eff) is dictated by the magnitude of V_(P1) and the polarityconfiguration of the polarity switch 682 while the value of V_(Eff) isless than or equal to −10 mV or greater than or equal to +10 mV. Butwhile the polarity switch 682 is in the high impedance mode, in therange when −10 mV<V_(E) 10 mV, the value of V_(Eff), and more generallythe values of V_(App1) and V_(App2), are determined based on predefinedcalculations or estimations.

Feedback Circuit

As described above, in some implementations the processing unit 604 canmodify the command signal V_(DCmnd) during operation (for example,during a tinting transition or during times between tinting transitions)based on one or more feedback signals V_(Feed). In some implementations,a feedback signal V_(Feed) is based on one or more voltage feedbacksignals V_(OC), which are in turn based on actual voltage levelsdetected across the ECDs of the connected IGUs. Such voltage feedbacksignals V_(OC) can be measured during periodic open circuit conditions(during or in between transitions) while the applied voltages V_(App1)and V_(App2) are turned off for brief durations of time. For example, anopen-circuit voltage feedback signal V_(OC) can be measured using adifferential amplifier 688 having a first input connected with powerline 634, a second input connected with power line 636, and an outputconnected with an analog-to-digital converter (ADC) 692. The ADC 692 canbe internal or external with respect to the processing unit 604. Oneexample of a differential amplifier suitable for use in someimplementations is the low power, adjustable gain, precision LT1991provided by Linear Technology Corp. of Milpitas, Calif.

Additionally or alternatively, a second feedback signal V_(Feed) can bebased on one or more current feedback signals V_(Cur), which are in turnbased on actual current levels detected through the ECDs. Such currentfeedback signals V_(Cur) can be measured using an operational amplifier690 having a first input connected with a first input terminal of aresistor 691, which is also connected to an output of the polarityswitch 682. A second input of the operational amplifier 690 can beconnected with a second terminal of the resistor 691, which is alsoconnected to a node at the second supply voltage V_(Sup2). The output ofthe operational amplifier 690 can be connected with the ADC 692. Oneexample of an operational amplifier suitable for use in someimplementations is the low noise, CMOS, precision AD8605 provided byAnalog Devices Inc. of Norwood, Mass. Because the resistance R_(F) ofthe resistor 691 is known, the actual current flowing out of thepolarity switch 682 can be determined by processing unit 604 based onthe voltage difference signal V_(Cur).

In some implementations, the processing unit 604 also is configured tocompensate for transmission losses resulting from the passage of thevoltage signals V_(App1) and V_(App2) through the conducting powerdistribution lines 633 and 635. More specifically, the actual voltagesprovided to the busbars of a given IGU 602 can be less than the voltagesV_(App1) and V_(App2) at the output of the WC 600. As such, the actualvoltage V_(Act) applied across the ECD within the IGU 402 can be lessthan the difference between the voltages V_(App1) and V_(App2) at theoutput of the WC 600. For example, the resistances of the powerdistribution lines 634 and 636—diagrammatically represented as resistorseach having resistance R_(T)—can result in significant voltage dropsalong the power distribution lines 634 and 636. The resistance of eachpower distribution line is, of course, directly proportional to thelength of the power distribution line and inversely proportional to thecross-sectional area of the power distribution line. An expected voltagedrop can thus be calculated based on knowledge of the length of thepower distribution lines. However, this length information is notnecessarily available. For example, installers may not record suchlength information during installation of the IGUs or may not recordsuch information accurately, precisely or correctly. Additionally, insome legacy installations where existing wires are utilized, such lengthinformation may not be available.

If information about the lengths of the power distribution lines isavailable, this information can be used to create a lookup table, forexample, that is stored in the memory chip within the plug-in component.This length information can then be read by the WC 600 upon power-up ofthe WC 600. In such implementations, the voltages V_(App1) and V_(App2)can be increased (for example, using firmware or software) to compensatefor the estimated voltage drops along the respective power distributionlines 634 and 636. While such compensation schemes and algorithms can beto some extent effective, such schemes and algorithms cannot preciselyaccount for the dynamic changes in the resistances of the powerdistribution lines resulting from changes in the temperatures of thepower distribution lines, which can change greatly in a given day basedon use of the power distribution lines, based on the position of the sunas the Earth spins, based on the weather, and based on the season.

Additionally or alternatively, a third feedback signal V_(Feed) can bebased on one or more voltage compensation signals V_(Comp), which are inturn based on an actual voltage drop detected along at least one of thepower distribution lines. For example, such voltage compensation signalsV_(Comp) can be measured using a differential amplifier 694 having afirst input connected with a one of the power distribution lines 634 or634 in the WC 600, a second input connected with the fifth line 642 inthe WC 600, and an output connected with the ADC 692. In some suchimplementations, such as that shown and described with reference to FIG.7, the plug-in component 752 includes a voltage compensation circuit762. In one example implementation, the voltage compensation circuit 762includes a conductor that provides a short between the fifth line 742and the first or the second power distribution line 734 or 736,respectively, within the plug-in component 752. In such animplementation, the differential amplifier 694 detects the offsetvoltage W_(Comp), which is proportional to the current I through thepower distribution line between the WC 600 and the IGU 602, as well asthe length of, and the cross-sectional area of, the power distributionline between the WC 600 and the IGU 602. The current I is determined bythe processing unit 604 based on the signal V_(Cur) output fromoperational amplifier 690. In this way, the processing unit can increaseor decrease the command voltage signal V_(DCmnd) to compensate for thestatic and dynamic voltage drops along the power distribution lineswithout having direct knowledge of the length or the cross-sectionalarea of the power distribution lines.

In one implementation, the resistance, R_(T), of each power distributionline between the WC 600 and the IGU 602 is calculated by dividingV_(Comp) by I. This resistance information is then stored in a parametertable within the WC 600. V_(Comp) is then dynamically calculated as2*R_(T)*V_(Cur). The voltage signals V_(App1) and V_(App2) cansubsequently dynamically adjusted automatically using the calculatedV_(Comp) amount to compensate for voltage drop in the lines 633 and 635.In another scenario, the voltage signals V_(App1) and V_(App2) areadjusted dynamically by 2*V_(Comp) to account for voltage drop in lines633 and 635.

Voltage compensation also is described in more detail in U.S. patentapplication Ser. No. 13/449,248 (Attorney Docket No. VIEWP041) filedApr. 17, 2012 and titled CONTROLLER FOR OPTICALLY SWITCHABLE WINDOWS,and U.S. patent application Ser. No. 13/449,251 (Attorney Docket No.VIEWP042) filed Apr. 17, 2012 and titled CONTROLLER FOR OPTICALLYSWITCHABLE WINDOWS, both of which are hereby incorporated by referencein their entireties and for all purposes. In some other implementations,a voltage compensation circuit 762 can be connected to communicationlines 739 and 741, which connect to the chip 756. In some otherimplementations, the voltage compensation circuit 762 can be directlycoupled with the communication lines 637 and 639 via the interface 754and the communication lines 738 and 740.

Each of the open-circuit voltage feedback signal V_(OC), the currentfeedback signal V_(Cur) and the voltage compensation feedback signalV_(Comp) can be digitized by the ADC 692 and provided to the processingunit 604 as a feedback signal V_(Feed). One example of an ADC suitablefor use in some implementations is the low power AD7902 by AnalogDevices Inc. of Norwood, Mass. In some instances above, while thefeedback signal V_(Feed) is referenced in the singular form, thefeedback signal V_(Feed) can collectively refer to three (or more orless) individual feedback signals: a first one for the digitizedopen-circuit voltage signal V_(OC), a second one for the digitizedcurrent signal V_(Cur), and a third one for the digitized voltagecompensation signal V_(Comp). The feedback signal V_(Feed) can beprovided to the processing unit 604 via the SPI bus 686. The processingunit 604 can then use the feedback signal V_(Feed) to dynamically modifythe command signal V_(DCmnd) such that the actual value V_(Act) of thevoltage applied across the ECD stack of the IGU 602 is approximatelyequal to the desired effective voltage V_(Eff), and thus, such that thetarget tint state is reached.

For example, as the outside environment becomes brighter, the WC 600 canreceive a tint command from the NC 500 to darken an IGU 602. However, insome implementations or instances, as the respective ECD becomesincreasingly more tinted, the temperature of the ECD can risesignificantly as a result of the increased photon absorption. Becausethe tinting of the ECD can be dependent on the temperature of the ECD,the tint state can change if the command signal V_(DCmnd) is notadjusted to compensate for the temperature change. In someimplementations, rather than detecting the temperature fluctuationdirectly, the processing unit 604 can adjust the command signalV_(DCmnd) based on the actual voltage detected across the ECD or theactual current detected through the ECD, as determined via the feedbacksignals V_(OC) and V_(Cur).

Additionally, as described above, each WC 600 can be connected to andpower a plurality of IGUs 602. While the cross-sectional areas of theset of power distribution lines that connect a given WC 600 to eachrespective one of the plurality of connected IGUs 602 are generally thesame, the lengths of each set of power distribution lines can bedifferent based on the location of the respective IGU 602 relative tothe WC 600. Thus, while the WC 600 provides the voltages V_(App1) andV_(App2) to the plurality of connected IGUs 602 via a common node (suchas through the coupling connecter 748 described above with reference toFIG. 7), the values of the voltages V_(App1) and V_(App2) actuallyreceived by each of the plurality of IGUs 602 can be different based onthe locations of the respective ones of the IGUs 402 relative to the WC600. In some implementations, it can be desirable that the powerdistribution lines connecting each of the IGUs 602 to a given WC 600have the same or similar length to reduce the disparities between theactual applied voltages received by the IGUs 602.

Communications Circuit

The communications circuit 612 is generally configured to enablecommunication between the processing unit 604 and various othercomponents within or outside of the WC 600. For example, thecommunications circuit 612 can include a bridge device 696. In someimplementations, the bridge device 696 enables the processing unit 696to communicate and receive data signals Data₃ and Data₄ overcommunication lines 638 and 640 (collectively referred to as data bus644), and corresponding communication lines 637 and 639. In someimplementations, the bridge device 696 can be a 1-Wire bridge deviceconfigured to communicate according to the 1-Wire communicationsprotocol. In some such implementations, the communication lines 639 and640 can be signal grounds, while the communication lines 637 and 639,which carry the data signal Data₃, can provide both data and power tothe chip 756 as well as to any number of 1-Wire-compatible sensorswithin the IGU 602. In some implementations, the chip 756 within the IGU602 can be an intermediary for communications of data between theprocessing unit 604 and the sensors within the IGU 602. For example, thesensors can be connected to communication lines 739 and 741, whichconnect to the chip 756. In some other implementations, the sensors canbe directly coupled with the communication lines 637 and 639 via theinterface 754 and the communication lines 738 and 740. At other times,the data signal Data₃ can communicate sensor data back to the processingunit 604.

The bridge device 696 is configured to manage the communications to,from and among the 1-Wire devices. The processing unit 604 cancommunicate instructions to the bridge device 696, or receive data fromthe bridge device, via an I²C bus 697. Although the I²C bus 697 may bedescribed herein in the singular form, the I²C bus 697 may collectivelyrefer to two or more I²C buses, each of which can be used to communicatewith a respective component of the WC 600. Thus, in someimplementations, the bridge device 696 functions as an I²C to 1-Wirebridge that interfaces directly to an I²C host port of the I²C master(the processing unit 604) to perform bidirectional protocol conversionbetween the processing unit 604 and the downstream 1-Wire slave devicesincluding the chip 756 and any sensors on or within the IGU 602. Onesuch bridge device suitable for use in some implementations is theDS2482 1-Wire Master device provided by Maxim Integrated Products, Inc.of San Jose, Calif. In some other implementations, the functions of thebridge device 696 can be integrated into the processing unit 604.

In some implementations, responsive to powering on or otherwiseactivating the processing unit 604, the processing unit 604 instructs,via the bridge device 696, the communication module 756 within theplug-in component 752 to transfer the device and drive parameters to theRAM or other memory device within the processing unit 604. Additionallyor alternatively, the processing unit 604 can periodically poll for thecommunication module 756 via the bridge device 696. The communicationmodule 756 can then respond to the poll by transferring the driveparameters to the RAM or other memory device within the WC 600 via thebridge device 696.

In some implementations, the communications circuit 612 also includes aradio transceiver 698. For example, the radio transceiver 698 cancommunicate with the processing unit 604 via the I²C bus 697. The radiotransceiver 698 can enable wireless communication between the processingunit 604 and other devices having such radio transceivers including, forexample, other WCs 600, the NC 500, the IGUs 602 as well as mobiledevices or other computing devices. While referred to herein in thesingular form, the radio transceiver 698 can collectively refer to oneor more radio transceivers each configured for wireless communicationaccording to a different respective protocol. For example, some wirelessnetwork protocols suitable for use in some implementations can be basedon the IEEE 802.11 standard, such as Wi-Fi (or “WiFi”). Additionally oralternatively, the radio transceiver 698 can be configured tocommunicate based on the IEEE 802.15.4 standard, which defines thephysical layer and media access control for low-rate wireless personalarea networks (LR-WPANs). For example, higher level protocols compatiblewith the IEEE 802.15.4 standard can be based on the ZigBee, 6LoWPAN,ISA100.11a, WirelessHART or MiWi specifications and standards.Additionally or alternatively, the radio transceiver 698 can beconfigured to communicate based on the Bluetooth standard (including theClassic Bluetooth, Bluetooth high speed and Bluetooth low energyprotocols and including the Bluetooth v4.0, v4.1 and v4.2 versions).Additionally or alternatively, the radio transceiver 698 can beconfigured to communicate based on the EnOcean standard (ISO/IEC14543-3-10).

As described above, wireless communication can take the place ofcommunication over physical cables between the WC 600 and the NC 500. Insome other implementations, both wired and wireless communications canbe established between the WC 600 and the NC 500. In other words, atleast two communication links of different types can be simultaneouslymaintained to send data between the WC and the MC. For instance, the WCcan be in wired communication with the NC using CANbus for some lessdata intensive messaging such as WC voltage data, current data andsensor data. At the same time, the WC can be in wireless communicationwith the NC via WiFi or other any wireless communication techniquedisclosed herein for more data intensive communications such as a videocamera feed and/or an audio feed. When two or more communication linksare maintained, one communication link can serve as a backup for theother in case of a disruption or other error condition. In someimplementations, sensors and other devices can be in communication withthe WC using a wireless link, a wired link or both. In someimplementations, the distributed WCs 600 can form a mesh network forcommunicating various information to one another or to the MC 400, theNC 500 or to other devices, rendering physical communication linesbetween the various controllers of a network system such as networksystem 300 unnecessary. As also noted above, the WC 600 can communicatewirelessly with the IGUs 602 it controls. For example, the communicationmodule 756 within each IGU 602 also can include a radio transceiver forcommunicating with the radio transceiver 698 and the processing unit 604of the WC 600. In some implementations, wireless communication can takethe place of communication over physical cables between the WC 600 andthe IGU 602. For example, wireless communication can take the place ofthe 1-Wire communication bus 644, the communication lines 637 and 639,and the communication lines 738 and 740. Such wireless implementationscan facilitate the manufacture and installation of self-contained IGUs,for example, IGUs that don't require the attachment of physical cables.In some such self-contained implementations, each IGU can include anenergy storage device and an integrated photovoltaic cell for chargingthe energy storage device. The energy storage device, in turn, can powerthe tint states and tint state transitions of the ECD within the IGU.

In some implementations, the communications circuit 612 can additionallyor alternatively include a power line communications module 699. Thepower line communications module 699 can be used in implementations orinstances in which data is communicated via the power supply voltagesignal V_(Sup1) (and in some cases, also V_(Sup2)) rather than, or inaddition to, over communications lines 622 and 624 or wirelessly. Asshown, the power line communications module 699 also can communicatewith the processing unit 604 via the I²C bus 697.

Auto-/Semiauto-Commissioning/Self-Discovery

In some implementations, after installation and after the WCs have beenturned on, the WCs can request or poll for the 1-Wire IDs within theIGUs 602. These 1-Wire IDs are then sent from the WC to the NC, andultimately to the MC so that the MC can associate the CANbus ID of theWC to the 1-Wire IDs of the IGUs it controls. In some otherimplementations, the IGUs also can include wireless transceivers. Forexample, a Bluetooth transceiver within each IGU can broadcast a beaconcontaining the ID of the IGU, which the WC can then pick up. Once theIDs of the IGUs connected with the WC are known, a person can thenproceed through the building with a mobile device (phone, IPad, orproprietary device) to associate each of the IGUs with a physicallocation.

Sleep Modes

In some implementations, the WC 600 is configured to enter and exit oneor more sleep modes in addition to the normal (or “active”) operatingmode. For example, after a target tint state has been reached and aholding voltage has been applied for a duration of time, the processingunit 604 can stop asserting (or “deassert”) the enable signal EN, andthus disable the HP downconverter 670. Because the HP down converter 670supplies power to most of the components within the WC 600, when theenable signal EN is deasserted, the WC 600 enters a first sleep mode.Alternatively, instead of turning off or disabling the HP down converter670, the processing unit can disable each of the components within theWC 600 individually or selectively in groups by deasserting other enablesignals (not shown) to such individual components or groups. In someimplementations, prior to disabling the HP down converter 670 orotherwise disabling the desired components within the WC 600, theprocessing unit 604 asserts a control signal Cntrl that causes thevoltage regulator 680 to enter a high impedance mode, for example, sothat when the other components are turned off, charge stored within theEC stacks of the connected IGUs 602 doesn't flow backwards from the IGUsinto the WC 600. In some implementations, the LP down converter 668remains on during the first sleep mode to provide full power to theprocessing unit 604. In some implementations, the processing unit 604can enable the differential amplifier 688 and the ADC 692 periodicallyto determine whether V_(OC) has fallen (or risen) below a thresholdlevel, for example, to determine whether the tint state of the IGU haschanged beyond an acceptable level. When V_(OC) has fallen below (orrisen above) the threshold, the processing unit 604 can “awaken” the WC600 (for example, exit the sleep mode and return to the normal activeoperating mode) by turning on the HP down converter 670 or otherwiseturning on the components necessary to drive the EC stack of the IGU toan acceptable level. In some implementations, upon exiting the sleepmode, the processing unit 604 can cause a voltage ramp to be applied tothe EC stack followed by a holding voltage.

In some implementations, the processing unit 604 can be configured tocause the WC 600 to enter a second (or “deep”) sleep mode different thanthe first (or “light”) sleep mode. For example, after the WC 600 hasbeen in the first sleep mode for a duration of time, the processing unit604 can disable some of its functionality to further save power. Ineffect, the processing unit 604 itself enters a sleep mode. Theprocessing unit 604 still gets the 3.3V from the LP down converter, butit configured in a reduced-functionality, low-power mode in which itconsumes significantly less power than in the normal fully functionalmode. While in such a second sleep mode, the processing unit 604 can beawakened in one or more of a number of ways. For example, the processingunit 604 can awaken itself periodically (such as every minute, every fewminutes, every 10 minutes). As described above, the processing unit 604can then enable the differential amplifier 688 and the ADC 692 todetermine whether V_(OC) has fallen below (or risen above) a thresholdlevel, for example, to determine whether the tint state of the IGU haschanged beyond an acceptable level. When V_(OC) has fallen below (orrisen above) the threshold, the processing unit 604 can awaken the WC600 by turning on the HP down converter 670 or otherwise turning on thecomponents necessary to drive the EC stack of the IGU to an acceptablelevel. In some implementations, upon exiting the sleep mode, theprocessing unit 604 can cause a voltage ramp to be applied to the ECstack followed by a holding voltage.

Additionally or alternatively, the processing unit 604 can be awakenedfrom such a deep sleep mode based on an interrupt such as a command fromNC 500 or based on a signal from an occupancy sensor communicativelycoupled with the processing unit 604. When such an occupancy sensordetects an occupant, the occupancy sensor can provide a signal to theprocessing unit 604 that causes the processing unit to awaken and returnthe WC 600 to the active mode (in some other implementations, theoccupancy sensor can be coupled with the NC 500 which then sends anawaken command to the WC 500 based on a signal from the occupancysensor). In some implementations, for example in scenarios in whichusers carry devices that include Bluetooth or other suitable types oftransceivers that periodically poll or send beacons for pairing, theprocessing unit 604 can periodically awaken to enable the radiotransceiver 698 to determine whether any such devices are in proximity.

Additionally, to further save power during such sleep modes, theprocessing unit 604 can enable the voltage regulator 680 via the controlsignal Cntrl to draw the power needed to power the processing unit 604and the radio transceiver 698 from the charge stored within the EC stackof the IGU 602. More examples of the use of power conservation andintelligent and efficient power distribution are described in PCT PatentApplication No. PCT/US16/41176 (Attorney Docket No. VIEWP080WO) filedJul. 6, 2016 and titled POWER MANAGEMENT FOR ELECTROCHROMIC WINDOWNETWORKS, which is hereby incorporated by reference in its entirety andfor all purposes. Additionally, subject matter related to obtainingV_(OC) is further described in U.S. patent application Ser. No.13/931,459 (Attorney Docket No. VIEWP052) filed Jun. 28, 2013 and titledCONTROLLING TRANSITIONS IN OPTICALLY SWITCHABLE DEVICES, which is herebyincorporated by reference in its entirety and for all purposes.

Smart Network Controller

In some implementations, the NC 500 described with reference to FIG. 5can take over some of the functions, processes or operations that aredescribed above as being responsibilities of the MC 400 of FIG. 4.Additionally or alternatively, the NC 500 can include additionalfunctionalities or capabilities not described with reference to the MC400. FIG. 8 shows a block diagram of example modules of a networkcontroller in accordance with some implementations. For example, themodules of FIG. 8 can be implemented in the NC 500 in any suitablecombination of hardware, firmware and software. In some implementationsin which the NC 500 is implemented as a network controller applicationexecuting within a computer, each of the modules of FIG. 9 also can beimplemented as an application, task or subtask executing within thenetwork controller application.

In some implementations, the NC 500 periodically requests statusinformation from the WCs 600 it controls. For example, the NC 500 cancommunicate a status request to each of the WCs 600 it controls everyfew seconds, every few tens of seconds, every minute, every few minutesor after any desirable period of time. In some implementations, eachstatus request is directed to a respective one of the WCs 600 using theCAN ID or other identifier of the respective WC 600. In someimplementations, the NC 500 proceeds sequentially through all of the WCs600 it controls during each round of status acquisition. In other words,the NC 500 loops through all of the WCs 600 it controls such that astatus request is sent to each of the WCs 600 sequentially in each roundof status acquisition. After a status request has been sent to a givenWC 600, the NC 500 then waits to receive the status information from therespective WC 600 before sending a status request to the next one of theWCs in the round of status acquisition.

In some implementations, after status information has been received fromall of the WCs 600 that the NC 500 controls, the NC 500 then performs around of tint command distribution. For example, in someimplementations, each round of status acquisition is followed by a roundof tint command distribution, which is then followed by a next round ofstatus acquisition and a next round of tint command distribution, and soon. In some implementations, during each round of tint commanddistribution, the NC 500 proceeds to send a tint command to each of theWCs 600 that the NC 500 controls. In some such implementations, the NC500 also proceeds sequentially through all of the WCs 600 it controlsduring the round of tint command distribution. In other words, the NC500 loops through all of the WCs 600 it controls such that a tintcommand is sent to each of the WCs 600 sequentially in each round oftint command distribution.

In some implementations, each status request includes instructionsindicating what status information is being requested from therespective WC 600. In some implementations, responsive to the receipt ofsuch a request, the respective WC 600 responds by transmitting therequested status information to the NC 500 (for example, via thecommunication lines in the upstream set of cables 616). In some otherimplementations, each status request by default causes the WC 600 totransmit a predefined set of information for the set of IGUs 602 itcontrols. Either way, the status information that the WC 600communicates to the NC 500 responsive to each status request can includea tint status value (S) for the IGUs 602, for example, indicatingwhether the IGUs 602 is undergoing a tinting transition or has finisheda tinting transition. Additionally or alternatively, the tint statusvalue S or another value can indicate a particular stage in a tintingtransition (for example, a particular stage of a voltage controlprofile). In some implementations, the status value S or another valuealso can indicate whether the WC 600 is in a sleep mode. The statusinformation communicated in response to the status request also caninclude the tint value (C) for the IGUs 602, for example, as set by theMC 400 or the NC 500. The response also can include a set point voltageset by the WC 600 based on the tint value (for example, the value of theeffective applied V_(Eff)). In some implementations, the response alsocan include a near real-time actual voltage level V_(Act) measured,detected or otherwise determined across the ECDs within the IGUs 602(for example, via the amplifier 688 and the feedback circuit 610). Insome implementations, the response also can include a near real-timeactual current level I_(Act) measured, detected or otherwise determinedthrough the ECDs within the IGUs 602 (for example, via the amplifier 690and the feedback circuit 610). The response also can include variousnear real-time sensor data, for example, collected from photosensors ortemperature sensors integrated on or within the IGUs 602.

Some protocols such as CANOpen limit the size of each frame of data sentfrom the WC 600 to the NC 500 and vice versa. In some instances, thesending of each status request and the receiving of status informationresponsive to such a request actually includes multiple two-waycommunications, and thus, multiple frames. For example, each statusrequest described above can include a separate sub-request for each ofthe status values described above. As a more specific example, eachstatus request from the NC 500 to a particular WC 600 can include afirst sub-request requesting the status value S. In response to thefirst sub-request, the WC 600 can transmit to the NC 500 anacknowledgement and a frame including the status value S. The NC 500 canthen transmit a second sub-request to the WC 600 requesting the tintvalue C. In response to the second sub-request, the WC 600 can transmitto the NC 500 an acknowledgement and a frame including the tint value C.The values of V_(Eff), V_(Act) and I_(Act) as well as sensor data cansimilarly be obtained with separate respective sub-requests andresponses.

In some other implementations, rather than polling or sending a statusrequest to each of the WCs 600 on a sequential basis, the NC 500 canasynchronously send status requests to particular WCs 600. For example,it may not be useful to receive status information (including C, S,V_(Eff), V_(Act) and I_(Act)) from all of the WC s 600 periodically. Forexample, it may be desirable to asynchronously request such informationfrom only particular ones of the WCs 600 that have recently received orimplemented a tint command, that are currently undergoing a tintingtransition, that have recently finished a tinting transition, or fromwhich status information has not been collected for a relatively longduration of time.

In some other implementations, rather than polling or sending statusrequests to each of the WCs 600 individually, whether on a sequentialbasis or asynchronously, each of the WC s 600 can periodically broadcastits status information (including C, S, V_(Eff), V_(Act) and I_(Act)).In some such implementations, each of the WCs 600 can broadcast thestatus information wirelessly. For example, each WC 600 can broadcastthe status information every few seconds, tens of seconds, minutes ortens of minutes. In some implementations, the WCs 600 can besynchronized to broadcast their respective status information at certaintimes to avoid occupying a large amount of collective bandwidth.Additionally, the broadcast period can be different for different sets(such as the zones described above) of WCs 600 and at different times,for example, based on the positions of the respective IGUs in thebuilding and relative to the sun, or based on whether the roomsadjoining the IGUs are occupied.

In some other implementations, each of the WCs 600 can broadcast itsstatus information in response to certain conditions, for example, whenstarting a tinting transition, when finishing a tinting transition, whenV_(Act) changes by a threshold, when I_(Act) changes by a threshold,when sensor data (for example, light intensity or temperature) changesby a threshold, when an occupancy sensor indicates the adjoining room isoccupied, or when entering or exiting a sleep mode. The NC 500 canlisten for such broadcasted status information, and when it hears it,record the status information. Advantageously, in broadcastingimplementations, the time required to receive status information from aset of WCs 600 is approximately cut in half because there is no need torequest the status information from the WCs 600, and thus, no roundtripdelay associated with each WC 600. Instead, there is only a one-waylatency associated with the time required to transmit the statusinformation from each WC 600 to the NC 500.

In some other implementations, at power on or thereafter, each of theWCs 600 can be configured to read device parameters, drive parametersand lite IDs or other ECD IDs for connected IGUs. The WCs then broadcasttheir CAN IDs as well as the lite IDs and the associated device anddrive parameters. That is, in some implementations, such broadcasting isinitiated by one or more processors in a WC without or irrespective ofany requests for such data by the NCs or other controllers. When the IDsand parameters are broadcast, the NC 500 can receive and process the IDsand parameters. In some implementations, lite IDs and parameters frommessages broadcasted by the WC are then communicated from the NC to theMC, which stores them, for example, in a table including a list of knownCAN IDs. For example, each row of the table can include a CAN ID, a WClocation ID associated with the CAN ID, the connected lite IDs, thelocations of the respective windows associated with the lite IDs, andthe device and drive parameters for the respective ECDs. In someimplementations, the MC can store the table in a cloud-based databasesystem so that even if the MC fails, another MC can be instantiated andaccess the table in the cloud.

In some instances, during commissioning, a field service technician mayintervene and attempt to perform ad hoc lite-to-lite matching based onperceived differences in the tints of two or more neighboring windows.In such cases, the technician may determine that the drive parametersfor one or more ECDs should be modified, and these modifications arethen implemented. In some implementations, the WC is configured tobroadcast the modified parameters to the corresponding NC, from whichthe parameters can be communicated to the MC. In situations where the WCthen fails or experiences an error, the NC or MC can determine that theWC has failed, for instance, because the WC is no longer broadcasting insituations where the WC has been configured to periodically broadcastdata such as the WC's CAN ID and/or WC location ID. When the failed WCis replaced with a new WC, which is then powered-on, the new WC willread the corresponding lite IDs and, as described above, broadcast thenew WC's CAN ID and the connected lite IDs. When the NC or MC receivesthis information, the NC or MC can be configured to retrieve themodified drive parameters for the failed WC from a database table byperforming a table look-up using the lite IDs. In such instances, the NCor MC is also configured to automatically update the table by assigningthe new CAN ID to the WC location ID and associated lite IDs. The NC orMC will then automatically communicate the modified drive parameters tothe new WC. In this way, the ECD which had its drive parameters modifiedduring commissioning can still be driven by the modified driveparameters even when the respective WC has been replaced. Othertechniques for automatically modifying, updating, and applying driveparameters can be performed in some implementations, as furtherdescribed in U.S. Provisional Patent Application No. 62/305,892, titledMETHOD OF COMMISSIONING ELECTROCHROMIC WINDOWS, by Shrivastava et al.,filed Mar. 9, 2016 (Attorney Docket No. VIEWP008X2P), which is herebyincorporated by reference in its entirety and for all purposes,

In some such implementations, rather than sending a tint command to eachof the WCs 600 on a sequential basis, the NC 500 can asynchronously senda tint command to a particular WC 600 whether through a wired orwireless connection. For example, it may not be useful to send tintcommands to all of the WCs 600 periodically. For example, it may bedesirable to asynchronously sent tint commands to only particular onesof the WCs 600 that are to be transitioned to a different tint state,for which status information has just been (or has recently been)received, or to which a tint command has not been sent for a relativelylong duration of time.

Data Logger

In some implementations, the NC 500 also includes a data logging module(or “data logger”) 802 for recording data associated with the IGUscontrolled by the NC 500. In some implementations, the data logger 802records the status information included in each of some or all of theresponses to the status requests. As described above, the statusinformation that the WC 600 communicates to the NC 500 responsive toeach status request can include a tint status value (S) for the IGUs602, a value indicating a particular stage in a tinting transition (forexample, a particular stage of a voltage control profile), a valueindicating whether the WC 600 is in a sleep mode, a tint value (C), aset point voltage set by the WC 600 based on the tint value (forexample, the value of the effective applied V_(Eff)), an actual voltagelevel V_(Act) measured, detected or otherwise determined across the ECDswithin the IGUs 602, an actual current level I_(Act) measured, detectedor otherwise determined through the ECDs within the IGUs 602, andvarious sensor data, for example, collected from photosensors ortemperature sensors integrated on or within the IGUs 602. In some otherimplementations, the NC 500 can collect and queue status information ina messaging queue like RabbitMC, ActiveMQ or Kafka and stream the statusinformation to the MC for subsequent processing such as datareduction/compression, event detection, etc., as further describedherein.

In some implementations, the data logger 802 within the NC 500 collectsand stores the various information received from the WCs 600 in the formof a log file such as a comma-separated values (CSV) file or via anothertable-structured file format. For example, each row of the CSV file canbe associated with a respective status request, and can include thevalues of C, S, V_(Eff), V_(Act) and I_(Act) as well as sensor data (orother data) received in response to the status request. In someimplementations, each row is identified by a timestamp corresponding tothe respective status request (for example, when the status request wassent by the NC 500, when the data was collected by the WC 600, when theresponse including the data was transmitted by the WC 600, or when theresponse was received by the NC 500). In some implementations, each rowalso includes the CAN ID or other ID associated with the respective WC600.

In some other implementations, each row of the CSV file can include therequested data for all of the WCs 600 controlled by the NC 500. Asdescribed above, the NC 500 can sequentially loop through all of the WCs600 it controls during each round of status requests. In some suchimplementations, each row of the CSV file is still identified by atimestamp (for example, in a first column), but the timestamp can beassociated with a start of each round of status requests, rather thaneach individual request. In one specific example, columns 2-6 canrespectively include the values C, S, V_(Eff), V_(Act) and I_(Act) for afirst one of the WCs 600 controlled by the NC 500, columns 7-11 canrespectively include the values C, S, V_(Eff), V_(Act) and I_(Act) for asecond one of the WCs 600, columns 12-16 can respectively include thevalues C, S, V_(Eff), V_(Act) and I_(Act) for a third one of the WCs600, and so on and so forth through all of the WCs 600 controlled by theNC 500. The subsequent row in the CSV file can include the respectivevalues for the next round of status requests. In some implementations,each row also can include sensor data obtained from photosensors,temperature sensors or other sensors integrated with the respective IGUscontrolled by each WC 600. For example, such sensor data values can beentered into respective columns between the values of C, S, V_(Eff),V_(Act) and I_(Act) for a first one of the WCs 600 but before the valuesof C, S, V_(Eff), V_(Act) and I_(Act) for the next one of the WCs 600 inthe row. Additionally or alternatively, each row can include sensor datavalues from one or more external sensors, for example, positioned on oneor more facades or on a rooftop of the building. In some suchimplementations, the NC 500 can send a status request to the externalsensors at the end of each round of status requests.

Compact Status

As described above, some protocols such as CANopen limit the size ofeach frame sent from the WC 600 to the NC 500 and vice versa. In someinstances, the sending of each status request and the receiving ofstatus information responsive to such a request actually includesmultiple two-way communications and frames. For example, each statusrequest described above can include a separate sub-request for each ofthe status values described above. In some implementations, each of twoor more of the requested values C, S, V_(Eff), V_(Act) and I_(Act) canbe transmitted together within a single response—a compact statusresponse. For example, in some implementations, the values of two ormore of C, S, V_(Eff), V_(Act) and I_(Act) are formatted so as to fit inone frame. For example, the CANopen protocol limits the size of the datapayload that can be sent in each frame to 8 bytes (where each byteincludes 8 bits). And in implementations in which the Service DataObject (SDO) sub-protocol of CAN open is used, the maximum size of thedata payload portion of the CANopen frame is 4 bytes (32 bits). In someimplementations, the size of each of the values V_(Eff), V_(Act) andI_(Act) is 10 bits. Thus, each of the values of V_(Eff), V_(Act) andI_(Act) can be packaged within a single SDO frame. This leaves 2 bitsleft over. In some implementations, each of the values of C and S can bespecified with one respective bit. In such case, all of the values of C,S, V_(Eff), V_(Act) and I_(Act) can be specified using only 32 bits, andthus, be packaged within one SDO CANopen frame.

In some implementations, additional time savings can be achieved using abroadcast status request. For example, rather than sending a statusrequest to each of the WCs 600 on an individual (or “unicast” basis),the NC 500 can broadcast a single status request to all of the WCs 600it controls. As described above, responsive to receiving the statusrequest, each WC 600 can be programmed to respond by communicatingstatus information such as the values C, S, V_(Eff), V_(Act) and I_(Act)in one or more compact status responses.

Protocol Conversion Module

As described above, one function of the NC 500 can be in translatingbetween various upstream and downstream protocols, for example, toenable the distribution of information between WCs 600 and the MC 400 orbetween the WCs and the outward-facing network 310. In someimplementations, a protocol conversion module 804 is responsible forsuch translation or conversion services. In various implementations, theprotocol conversion module 904 can be programmed to perform translationbetween any of a number of upstream protocols and any of a number ofdownstream protocols. As described above, such upstream protocols caninclude UDP protocols such as BACnet, TCP protocols such as oBix, otherprotocols built over these protocols as well as various wirelessprotocols. Downstream protocols can include, for example, CANopen, otherCAN-compatible protocol, and various wireless protocols including, forexample, protocols based on the IEEE 802.11 standard (for example,WiFi), protocols based on the IEEE 802.15.4 standard (for example,ZigBee, 6LoWPAN, ISA100.11a, WirelessHART or MiWi), protocols based onthe Bluetooth standard (including the Classic Bluetooth, Bluetooth highspeed and Bluetooth low energy protocols and including the Bluetoothv4.0, v4.1 and v4.2 versions), or protocols based on the EnOceanstandard (ISO/IEC 14543-3-10).

Integrated Analytics

In some implementations, the NC 500 uploads the information logged bythe data logger 802 (for example, as a CSV file) to the MC 400 on aperiodic basis, for example, every 24 hours. For example, the NC 500 cantransmit a CSV file to the MC 400 via the File Transfer Protocol (FTP)or another suitable protocol over an Ethernet data link 316. In somesuch implementations, the status information can then be stored in thedatabase 320 or made accessible to applications over the outward-facingnetwork 310.

In some implementations, the NC 500 also can include functionality toanalyze the information logged by the data logger 802. For example, ananalytics module 906 can receive and analyze the raw information loggedby the data logger 802 in real time. In various implementations, theanalytics module 806 can be programmed to make decisions based on theraw information from the data logger 802. In some other implementations,the analytics module 806 can communicate with the database 320 toanalyze the status information logged by the data logger 802 after it isstored in the database 320. For example, the analytics module 806 cancompare raw values of electrical characteristics such as V_(Eff),V_(Act) and I_(Act) with expected values or expected ranges of valuesand flag special conditions based on the comparison. For example, suchflagged conditions can include power spikes indicating a failure such asa short, an error, or damage to an ECD. In some implementations, theanalytics module 806 communicates such data to the tint determinationmodule 810 or to the power management module 812.

In some implementations, the analytics module 806 also can filter theraw data received from the data logger 802 to more intelligently orefficiently store information in the database 320. For example, theanalytics module 806 can be programmed to pass only “interesting”information to a database manager 808 for storage in the database 320.For example, interesting information can include anomalous values,values that otherwise deviate from expected values (such as based onempirical or historical values), or for specific periods whentransitions are happening. More detailed examples of how raw data can befiltered, parsed, temporarily stored, and efficiently stored long termin a database are described in PCT Patent Application No.PCT/2015/029675 (Attorney Docket No. VIEWP049X1WO) filed May 7, 2015 andtitled CONTROL METHOD FOR TINTABLE WINDOWS, which is hereby incorporatedby reference in its entirety and for all purposes.

Database Manager

In some implementations, the NC 500 includes a database manager module(or “database manager”) 808 configured to store information logged bythe data logger 804 to a database on a periodic basis, for example,every hour, every few hours or every 24 hours. In some implementations,the database can be an external database such as the database 320described above. In some other implementations, the database can beinternal to the NC 500. For example, the database can be implemented asa time-series database such as a Graphite database within the secondarymemory 506 of the NC 500 or within another long term memory within theNC 500. In some example implementations, the database manager 808 can beimplemented as a Graphite Daemon executing as a background process,task, sub-task or application within a multi-tasking operating system ofthe NC 500. A time-series database can be advantageous over a relationaldatabase such as SQL because a time-series database is more efficientfor data analyzed over time

In some implementations, the database 320 can collectively refer to twoor more databases, each of which can store some or all of theinformation obtained by some or all of the NCs 500 in the network system300. For example, it can be desirable to store copies of the informationin multiple databases for redundancy purposes. In some implementations,the database 320 can collectively refer to a multitude of databases,each of which is internal to a respective NC 500 (such as a Graphite orother times-series database). It also can be desirable to store copiesof the information in multiple databases such that requests forinformation from applications including third party applications can bedistributed among the databases and handled more efficiently. In somesuch implementations, the databases can be periodically or otherwisesynchronized to maintain consistency.

In some implementations, the database manager 808 also can filter datareceived from the analytics module 806 to more intelligently orefficiently store information in an internal or external database. Forexample, the database manager 808 can additionally or alternatively beprogrammed to store only “interesting” information to a database. Again,interesting information can include anomalous values, values thatotherwise deviate from expected values (such as based on empirical orhistorical values), or for specific periods when transitions arehappening. More detailed examples of how raw data can be filtered,parsed, temporarily stored, and efficiently stored long term in adatabase are described in PCT Patent Application No. PCT/2015/029675(Attorney Docket No. VIEWP049X1WO) filed May 7, 2015 and titled CONTROLMETHOD FOR TINTABLE WINDOWS, which is hereby incorporated by referencein its entirety and for all purposes.

Tint Determination

In some implementations, the NC 500 or the MC 400 includes intelligencefor calculating, determining, selecting or otherwise generating tintvalues for the IGUs 602. For example, as similarly described above withreference to the MC 400 of FIG. 4, a tint determination module 810 canexecute various algorithms, tasks or subtasks to generate tint valuesbased on a combination of parameters. The combination of parameters caninclude, for example, the status information collected and stored by thedata logger 802. The combination of parameters also can include time orcalendar information such as the time of day, day of year or time ofseason. Additionally or alternatively, the combination of parameters caninclude solar calendar information such as, for example, the directionof the sun relative to the IGUs 602. The combination of parameters alsocan include the outside temperature (external to the building), theinside temperature (within a room adjoining the target IGUs 602), or thetemperature within the interior volume of the IGUs 602. The combinationof parameters also can include information about the weather (forexample, whether it is clear, sunny, overcast, cloudy, raining orsnowing). Parameters such as the time of day, day of year, or directionof the sun can be programmed into and tracked by the NC 500. Parameterssuch as the outside temperature, inside temperature or IGU temperaturecan be obtained from sensors in, on or around the building or sensorsintegrated on or within the IGUs 602. In some implementations, variousparameters can be provided by, or determined based on informationprovided by, various applications including third party applicationsthat can communicate with the NC 500 via an API. For example, thenetwork controller application, or the operating system in which itruns, can be programmed to provide the API.

In some implementations, the tint determination module 810 also candetermine tint values based on user overrides received via variousmobile device applications, wall devices or other devices. In someimplementations, the tint determination module 810 also can determinetint values based on commands or instructions received variousapplications, including third party applications and cloud-basedapplications. For example, such third party applications can includevarious monitoring services including thermostat services, alertservices (for example, fire detection), security services or otherappliance automation services. Additional examples of monitoringservices and systems can be found in PCT/US2015/019031 (Attorney DocketNo. VIEWP061WO) filed 5 Mar. 2015 and titled MONITORING SITES CONTAININGSWITCHABLE OPTICAL DEVICES AND CONTROLLERS. Such applications cancommunicate with the tint determination module 810 and other moduleswithin the NC 500 via one or more APIs. Some examples of APIs that theNC 500 can enable are described in U.S. Provisional Patent ApplicationSer. No. 62/088,943 (Attorney Docket No. VIEWP073P) filed 8 Dec. 2014and titled MULTIPLE INTERFACING SYSTEMS AT A SITE.

Power Management

As described above, the analytics module 806 can compare values ofV_(Eff), V_(Act) and I_(Act) as well as sensor data either obtained inreal time or previously stored within the database 320 with expectedvalues or expected ranges of values and flag special conditions based onthe comparison. The analytics module 806 can pass such flagged data,flagged conditions or related information to the power management 812.For example, such flagged conditions can include power spikes indicatinga short, an error, or damage to an ECD. The power management module 812can then modify operations based on the flagged data or conditions. Forexample, the power management module 812 can delay tint commands untilpower demand has dropped, stop commands to troubled WCs (and put them inidle state), start staggering commands to WCs, manage peak power, orsignal for help.

CONCLUSION

In one or more aspects, one or more of the functions described may beimplemented in hardware, digital electronic circuitry, analog electroniccircuitry, computer software, firmware, including the structuresdisclosed in this specification and their structural equivalentsthereof, or in any combination thereof. Certain implementations of thesubject matter described in this document also can be implemented as oneor more controllers, computer programs, or physical structures, forexample, one or more modules of computer program instructions, encodedon a computer storage media for execution by, or to control theoperation of window controllers, network controllers, and/or antennacontrollers. Any disclosed implementations presented as or forelectrochromic windows can be more generally implemented as or forswitchable optical devices (including windows, mirrors, etc.).

Various modifications to the embodiments described in this disclosuremay be readily apparent to those skilled in the art, and the genericprinciples defined herein may be applied to other implementationswithout departing from the spirit or scope of this disclosure. Thus, theclaims are not intended to be limited to the implementations shownherein, but are to be accorded the widest scope consistent with thisdisclosure, the principles and the novel features disclosed herein.Additionally, a person having ordinary skill in the art will readilyappreciate, the terms “upper” and “lower” are sometimes used for ease ofdescribing the figures, and indicate relative positions corresponding tothe orientation of the figure on a properly oriented page, and may notreflect the proper orientation of the devices as implemented.

Certain features that are described in this specification in the contextof separate implementations also can be implemented in combination in asingle implementation. Conversely, various features that are describedin the context of a single implementation also can be implemented inmultiple implementations separately or in any suitable subcombination.Moreover, although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this does not necessarily mean that the operations are requiredto be performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. Further, the drawings may schematically depict one more exampleprocesses in the form of a flow diagram. However, other operations thatare not depicted can be incorporated in the example processes that areschematically illustrated. For example, one or more additionaloperations can be performed before, after, simultaneously, or betweenany of the illustrated operations. In certain circumstances,multitasking and parallel processing may be advantageous. Moreover, theseparation of various system components in the implementations describedabove should not be understood as requiring such separation in allimplementations, and it should be understood that the described programcomponents and systems can generally be integrated together in a singlesoftware product or packaged into multiple software products.Additionally, other implementations are within the scope of thefollowing claims. In some cases, the actions recited in the claims canbe performed in a different order and still achieve desirable results.

What is claimed is:
 1. An apparatus for controlling a facility, theapparatus comprising: an interface for communicating with windowcontrollers that are communicatively coupled to a control networkconfigured to control the facility; and a network controller operativelycoupled to the window controllers and to the interface, which networkcontroller is included in the control network, which network controlleris configured to cause: (i) sending a status request from the networkcontroller to one or more of the window controllers, the status requestrequesting a current tint status of one or more optically switchabledevices that are disposed in the facility and that are controlled by oneor more of the window controllers, (ii) processing status informationreceived at the network controller from the one or more of the windowcontrollers responsive to the status request, the status informationindicating at least the current tint status of the one or more opticallyswitchable devices controlled by the one or more of the windowcontrollers, and (iii) sending, responsive to processing the statusinformation, one or more tint commands via the interface to the one ormore of the window controllers.
 2. The apparatus of claim 1, wherein thenetwork controller is configured to send status requests to the one ormore of the window controllers on a sequential basis or on anasynchronous basis.
 3. The apparatus of claim 2, wherein the statusrequests are sent on the asynchronous basis based at least in part on atime duration that has elapsed since the one or more window controllersreceived one or more previously transmitted tint commands.
 4. Theapparatus of claim 1, wherein the network controller is configured tosend the one or more tint commands on a sequential basis to the one ormore of the window controllers.
 5. The apparatus of claim 1, wherein thestatus information further indicates voltage information associated withthe one or more of the optically switchable devices.
 6. The apparatus ofclaim 1, wherein the network controller is further configured to causethe status information to be stored in a log file in connection withsensor data received responsive to the status request.
 7. The apparatusof claim 1, wherein the status information received is utilized todetect at least one error condition of at least one of the one or moreoptically switchable devices.
 8. The apparatus of claim 1, wherein thecontrol network is configured to control at least one system of thefacility comprising: a heating, ventilation, and air conditioning (HVAC)system; a lighting system; a security system; an elevator system; a firesystem; and/or a power system.
 9. The apparatus of claim 8, wherein thecontrol network is configured to control two or more systems of thefacility, and wherein the control network is configured to optimizeusage of the two or more systems based on energy consumption of thefacility.
 10. A method for controlling a facility, the methodcomprising: sending, by a network controller to one or more windowcontrollers, a status request requesting a current tint status of one ormore optically switchable devices that are disposed in the facility andthat are controlled by one or more of the window controllers; processingstatus information received from the one or more of the windowcontrollers responsive to the status request, the status informationindicating at least the current tint status of the one or more opticallyswitchable devices controlled by the one or more of the windowcontrollers; and sending, responsive to processing the statusinformation, one or more tint commands via the interface to the one ormore of the window controllers.
 11. The method of claim 10, wherein thestatus requests are sent to the one or more of the window controllers ona sequential basis or on an asynchronous basis.
 12. The method of claim11, wherein the status requests are sent on the asynchronous basis basedat least in part on a time duration that has elapsed since the one ormore window controllers received one or more previously transmitted tintcommands.
 13. The method of claim 10, one or more tint commands are senton a sequential basis to the one or more of the window controllers. 14.The method of claim 10, wherein the status information further indicatesvoltage information associated with the one or more of the opticallyswitchable devices.
 15. The method of claim 10, further comprisingcausing the status information to be stored in a log file in connectionwith sensor data received responsive to the status request.
 16. Themethod of claim 10, further comprising utilizing the status informationreceived to detect at least one error condition of at least one of theone or more optically switchable devices.
 17. A method for controllingat least one tintable window, the method comprising: controlling tint ofthe at least one tintable window using a network that is (A) operativelycoupled to redundant controllers, (B) operatively coupled to (I) an airflow sensor and/or (II) an occupancy sensor configured to detectoccupant presence, and/or (C) is configured to (a) consider a surfacearea of the at least one tintable window and (b) adjust powerrequirements nonlinearly with respect to the surface area, which powerrequirements are for tinting the at least one tintable window.
 18. Themethod of claim 17, wherein the redundant controllers are part of ahierarchical control system.
 19. The method of claim 17, wherein atleast one controller of the redundant controllers is configured todetect an error condition.
 20. The method of claim 19, wherein the errorcondition comprises a power spike, a short condition, or damage to theat least one tintable window.
 21. The method of claim 19, wherein theerror condition is detected based at least on a comparison of (i) rawvalues of electrical characteristics and (ii) expected values of theelectrical characteristics.
 22. The method of claim 19, wherein the atleast one controller is configured to communicate data indicating theerror condition to a power management module.
 23. The method of claim17, wherein at least one controller of the redundant controllers isconfigured to poll the at least one tintable window for an identifier ofthe at least one tintable window.
 24. The method of claim 23, whereinthe identifier is transmitted as a wireless beacon.
 25. An apparatus forcontrolling at least one tintable window, the apparatus comprising atleast one controller configured to: control tint of the at least onetintable window using a network that is (A) operatively coupled toredundant controllers including the at least one controller, (B)operatively coupled to (I) an air flow sensor and/or (II) an occupancysensor configured to detect occupant presence, and/or (C) is configuredto (a) consider a surface area of the at least one tintable window and(b) adjust power requirements nonlinearly with respect to the surfacearea, which power requirements are for tinting the at least one tintablewindow
 26. The apparatus of claim 25, wherein the redundant controllersare part of a hierarchical control system.
 27. The apparatus of claim25, wherein at least one controller of the redundant controllers isconfigured to detect an error condition.
 28. The apparatus of claim 27,wherein the error condition comprises a power spike, a short condition,or damage to the at least one tintable window.
 29. The apparatus ofclaim 27, wherein the error condition is detected based at least on acomparison of (i) raw values of electrical characteristics and (ii)expected values of the electrical characteristics.
 30. The apparatus ofclaim 27, wherein the at least one controller is configured tocommunicate data indicating the error condition to a power managementmodule.
 31. The apparatus of claim 25, wherein at least one controllerof the redundant controllers is configured to poll the at least onetintable window for an identifier of the at least one tintable window.32. The apparatus of claim 31, wherein the identifier is transmitted asa wireless beacon.